CN102055335A - Buck-boost power converter and its control method - Google Patents

Buck-boost power converter and its control method Download PDF

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Publication number
CN102055335A
CN102055335A CN2009102120789A CN200910212078A CN102055335A CN 102055335 A CN102055335 A CN 102055335A CN 2009102120789 A CN2009102120789 A CN 2009102120789A CN 200910212078 A CN200910212078 A CN 200910212078A CN 102055335 A CN102055335 A CN 102055335A
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signal
switch
buck
power converter
mode
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CN102055335B (en
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陈科宏
吴纬权
何心欣
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Richtek Technology Corp
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Richtek Technology Corp
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Abstract

A method for controlling a buck-boost power converter, the power converter including an inductor, a first switch coupled between an input of the power converter and a first terminal of the inductor, a second switch coupled between the first terminal of the inductor and a ground terminal, a third switch coupled between a second terminal of the inductor and the ground terminal, and a fourth switch coupled between the second terminal of the inductor and an output of the power converter, the method comprising: detecting voltages at the input end and the output end and a load current at the output end to determine that the power converter operates in a buck mode, a first buck-boost mode, a second buck-boost mode or a boost mode; and controlling the first switch, the second switch, the third switch and the fourth switch in the first and second lifting and pressing modes.

Description

Step-down/up type power supply changeover device and control method thereof
Technical field
The present invention relates to a kind of power supply changeover device, specifically, is a kind of step-down/up type power supply changeover device and control method thereof of improving switch cost and correct switch mode.
Background technology
Fig. 1 shows known step-down/up type power supply changeover device 10, and it comprises power stage 12 and control circuit 14.In power stage 12, switch SW 1 is connected between input voltage vin and the inductance L, and switch SW 2 is connected between inductance L and the earth terminal GND, and switch SW 3 is connected between inductance L and the earth terminal GND, and switch SW 4 is connected between inductance L and the output voltage V out.Resistance R 1 and R2 pressure-dividing output voltage Vout produce feedback signal VFB, in control circuit 14, error amplifier 24 produces error signal VEA according to feedback signal VFB and reference voltage Vref, sawtooth generator 22 provides two sawtooth signal SAW1 and SAW2, comparator 18 comparison error signal VEA and sawtooth signal SAW1 produce signal PWM1, comparator 20 comparison error signal VEA and sawtooth signal SAW2 produce signal PWM2, and control logic circuit 16 produces signal VA according to signal PWM1 and PWM2, VB, VC and VD be diverter switch SW1 respectively, SW2, SW3 and SW4 are to transfer input voltage vin to output voltage V out.When error signal VEA only switched to sawtooth signal SAW1 or SAW2, power supply changeover device 10 operated in decompression mode or boost mode, and when error signal VEA switched to two sawtooth signal SAW1 or SAW2, power supply changeover device 10 operated in the buck pattern.Yet, in fact, the waveform of sawtooth signal SAW1 and SAW2 is not an ideal linearity at peak value and valley, therefore, in input voltage vin during near output voltage V out, just the responsibility cycle of signal PWM1 or PWM2 near 100% o'clock, will make the ripple of output voltage V out become big than (duty ratio) because of nonlinear problem.
People such as Chen are at U.S. Patent number the 7th, 176, a kind of step-down/up type power supply changeover device is proposed in No. 667, it is when the buck pattern, utilize a sawtooth signal and error signal to cut out the responsibility cycle of needed buck or boost, and within described responsibility cycle, insert fixing boosting or the step-down responsibility cycle.Yet, no matter be the power supply changeover devices that the people proposed such as Fig. 1 or Chen, when the buck pattern, the switching circulation of switch is opened (turn on) switch SW 2 and SW4 and is closed (turn off) switch SW 1 and SW3 for (1), (2) open switch SW 1 and SW4 and off switch SW2 and SW3, (3) open switch SW 1 and SW3 and off switch SW2 and SW4, (4) open switch SW 1 and SW4 and off switch SW2 and SW3, because the number of times that switch switches in each cycle is more, so switch cost (switching loss) is also bigger.
Therefore known step-down/up type power supply changeover device exists above-mentioned all inconvenience and problem.
Summary of the invention
Purpose of the present invention is to propose a kind ofly to use new switching sequence at input voltage during near output voltage, reduces the step-down/up type power supply changeover device and the control method thereof of switch cost and conducting loss.
Another object of the present invention is to propose a kind ofly to prolong the switching cycle of switch to reduce the step-down/up type power supply changeover device and the control method thereof of switch cost at input voltage during near output voltage.
A further object of the present invention is to propose a kind ofly to consider that load current makes it can be at correct some switch mode to the influence of buck responsibility cycle, thus output voltage can be because of the change pattern affected step-down/up type power supply changeover device and control method thereof.
For achieving the above object, technical solution of the present invention is:
A kind of control method of step-down/up type power supply changeover device, described power supply changeover device comprises an inductance, one first switch is connected between first end of the input of described power supply changeover device and described inductance, one second switch is connected between first end and an earth terminal of described inductance, one the 3rd switch is connected between second end and described earth terminal of described inductance, and one the 4th switch be connected between the output of second end of described inductance and described power supply changeover device, it is characterized in that described control method comprises the following steps:
First step: the voltage and the load current on described output that detect on described input and the output operate in decompression mode, the first buck pattern, second buck pattern or the boost mode to determine described power supply changeover device;
Second step: when described first and second buck pattern, described first, second, third and the control of the 4th switch comprise:
(a) close described first switch, open described second switch, close described the 3rd switch, open described the 4th switch;
(b) open described first switch, close described second switch, keep described the 3rd switch and close, keep described the 4th switch opens;
(c) keep described first switch opens, keep described second switch and close, open described the 3rd switch, close described the 4th switch.
The control method of step-down/up type power supply changeover device of the present invention can also be further achieved by the following technical measures.
The step that aforesaid control method, the described power supply changeover device of wherein said decision operate in decompression mode, the first buck pattern, the second buck pattern or boost mode comprises the following steps:
First step: the multiplier value at the described inductance two ends that voltage and load current determined on described input and output determines described power supply changeover device to operate in decompression mode less than one first critical value;
Second step: the multiplier value at the described inductance two ends that voltage and load current determined on described input and output determines described power supply changeover device to operate in the described first buck pattern greater than described first critical value and less than one second critical value;
Third step: the multiplier value at the described inductance two ends that voltage and load current determined on described input and output determines described power supply changeover device to operate in the described second buck pattern less than one the 3rd critical value and greater than described second critical value;
The 4th step:, determine described power supply changeover device to operate in described boost mode when the multiplier value at the described inductance two ends that voltage and load current determined on described input and the output during greater than described the 3rd critical value.
Aforesaid control method wherein more comprises:
The difference of amplifying one first letter and reaching between the reference voltage produces a secondary signal, and described first signal is the function of voltage on the described output;
One first frequency and a second frequency are provided;
Operator scheme and described first frequency according to described power supply changeover device produce one the 3rd signal and one the 4th signal;
More described secondary signal and the 3rd signal produce one the 5th signal;
More described secondary signal and the 4th signal produce one the 6th signal;
Operator scheme, the described the 5th and the 6th signal, first frequency and second frequency according to described power supply changeover device are controlled the described first, second, third and the 4th switch.
Aforesaid control method, wherein when described decompression mode, the switching cycle of described first and second switch is a period 1; When the described first buck pattern described first, second, third and the switching cycle of the 4th switch be a second round greater than the described period 1; When the described second buck pattern described first, second, third and the switching cycle of the 4th switch be a period 3 greater than the described period 1; When described boost mode the described the 3rd and the switching cycle of the 4th switch be a period 4 less than described second and third cycle.
Aforesaid control method, wherein when the described first buck pattern, the described the 3rd and the responsibility cycle of the 4th switch fix.
Aforesaid control method, wherein when the described second buck pattern, the responsibility cycle of described first and second switch is fixed.
A kind of step-down/up type power supply changeover device is characterized in that, comprising:
One inductance;
One first switch is connected between first end of the input of described power supply changeover device and described inductance;
One second switch is connected between first end and an earth terminal of described inductance;
One the 3rd switch is connected between second end and described earth terminal of described inductance;
One the 4th switch is connected between the output of second end of described inductance and described power supply changeover device;
One control circuit, control described first, second, third and the switching of the 4th switch, and determine described power supply changeover device to operate in decompression mode, the first buck pattern, second buck pattern or the boost mode according to the load current on voltage on described input and the output and the described output;
Wherein, when described first and second buck pattern, described first, second, third and the control of the 4th switch comprise (a) and close described first switch, open described second switch, close described the 3rd switch and open described the 4th switch, (b) open described first switch, close described second switch, keep described the 3rd switch and close and keep described the 4th switch opens, and (c) keep described first switch opens, keep described second switch and close, open described the 3rd switch and close described the 4th switch.
Aforesaid power supply changeover device, the multiplier value at the described inductance two ends that voltage and described load current determined of wherein said control circuit on described input and output determines described power supply changeover device to operate in described decompression mode during less than one first critical value; The multiplier value at the described inductance two ends that voltage and described load current determined on described input and output determines described power supply changeover device to operate in the described first buck pattern during greater than described first critical value and less than one second critical value; The multiplier value at the described inductance two ends that voltage and described load current determined on described input and output determines described power supply changeover device to operate in the described second buck pattern during less than one the 3rd critical value and greater than described second critical value; The multiplier value at the described inductance two ends that voltage and load current determined on described input and output determines described power supply changeover device to operate in described boost mode during greater than described the 3rd critical value.
Aforesaid power supply changeover device, wherein said control circuit comprises:
One error amplifier produces a secondary signal according to one first signal and a reference voltage, and described first signal is the function of voltage on the described power supply changeover device output;
One frequency generator provides a first frequency and a second frequency;
One mode detector detects the input of described power supply changeover device and the voltage on the output and produces one the 3rd signal and operate in decompression mode, the first buck pattern, second buck pattern or the boost mode to determine described power supply changeover device;
One sawtooth generator provides one the 4th signal or one the 5th signal according to described the 3rd signal and first frequency;
One first comparator, more described secondary signal and described the 4th signal produce one the 6th signal;
One second comparator, more described secondary signal and described the 5th signal produce one the 7th signal;
One control logic circuit is according to the switching of described the 3rd, the 6th and the 7th signal and first and second FREQUENCY CONTROL described first, second, third and the 4th switch.
Aforesaid power supply changeover device, wherein said control logic circuit comprises:
One frequency eliminator produces one the 3rd frequency to described first frequency frequency elimination;
One first logical circuit produces one first control signal, second control signal, the 3rd control signal and the 4th control signal according to described the 6th signal, first frequency, second frequency, the 3rd frequency and one second reference voltage;
One first multiplexer is chosen the switching that one of them controls described first and second switch according to described three signals from the described first, second, third and the 4th control signal;
One second logical circuit produces one the 5th control signal, the 6th control signal, the 7th control signal and the 8th control signal according to described the 7th signal, first frequency, the 3rd frequency and one the 3rd reference voltage;
One second multiplexer is chosen one of them according to described the 3rd signal and is controlled the described the 3rd and the switching of the 4th switch from described the 5th, the 6th, the 7th and the 8th control signal.
Aforesaid power supply changeover device, wherein said frequency eliminator comprise D type flip-flop.
Aforesaid power supply changeover device, wherein when described decompression mode, the switching cycle of described first and second switch is a period 1; When the described first buck pattern described first, second, third and the switching cycle of the 4th switch be a second round greater than the described period 1; When the described second buck pattern described first, second, third and the switching cycle of the 4th switch be a period 3 greater than the described period 1; When described boost mode the described the 3rd and the switching cycle of the 4th switch be a period 4 less than described second and third cycle.
Aforesaid power supply changeover device, wherein when the described first buck pattern, the described the 3rd and the responsibility cycle of the 4th switch fix.
Aforesaid power supply changeover device, wherein when the described second buck pattern, the responsibility cycle of described first and second switch is fixed.
A kind of control method of step-down/up type power supply changeover device, described power supply changeover device comprises an inductance, one first switch is connected between first end of the input of described power supply changeover device and described inductance, one second switch is connected between first end and an earth terminal of described inductance, one the 3rd switch is connected between second end and described earth terminal of described inductance, and one diode have an anode and connect second end of described inductance and the output that a negative electrode connects described power supply changeover device, it is characterized in that described control method comprises the following steps:
First step: the voltage and the load current on the described output that detect on described input and the output operate in decompression mode, the first buck pattern, second buck pattern or the boost mode to determine described power supply changeover device;
Second step: when described first and second buck pattern, the control of described first, second and third switch comprises:
(a) close described first switch, open described second switch, close described the 3rd switch;
(b) open described first switch, close described second switch, keep described the 3rd switch and close;
(c) keep described first switch opens, keep described second switch and close, open described the 3rd switch.
The step that aforesaid control method, the described power supply changeover device of wherein said decision operate in decompression mode, the first buck pattern, the second buck pattern or boost mode comprises:
When the multiplier value at the described inductance two ends that load current determined on voltage on described input and the output and the described output during, determine described power supply changeover device to operate in decompression mode less than one first critical value;
When the multiplier value at the described inductance two ends that load current determined on voltage on described input and the output and the described output during, determine described power supply changeover device to operate in the described first buck pattern greater than described first critical value and less than one second critical value;
When the multiplier value at the described inductance two ends that load current determined on voltage on described input and the output and the described output during, determine described power supply changeover device to operate in the described second buck pattern less than one the 3rd critical value and greater than described second critical value; When the multiplier value at the described inductance two ends that load current determined on voltage on described input and the output and the described output during, determine described power supply changeover device to operate in described boost mode greater than described the 3rd critical value.
Aforesaid control method wherein more comprises:
The difference of amplifying between one first signal and the reference voltage produces a secondary signal, and described first signal is the function of voltage on the described output;
One first frequency and a second frequency are provided;
Operator scheme and described first frequency according to described power supply changeover device produce one the 3rd signal and one the 4th signal;
More described secondary signal and the 3rd signal produce one the 5th signal;
More described secondary signal and the 4th signal produce one the 6th signal;
Operator scheme, the described the 5th and the 6th signal, first frequency and second frequency according to described power supply changeover device are controlled described first, second and third switch.
Aforesaid control method, wherein when described decompression mode, the switching cycle of described first and second switch is a period 1; The switching cycle of described first, second and third switch is a second round greater than the described period 1 when the described first buck pattern; The switching cycle of described first, second and third switch is a period 3 greater than the described period 1 when the described second buck pattern; The switching cycle of described the 3rd switch is a period 4 less than described second and third cycle when described boost mode.
Aforesaid control method, wherein when the described first buck pattern, the responsibility cycle of described the 3rd switch is fixed.
Aforesaid control method, wherein when the described second buck pattern, the responsibility cycle of described first and second switch is fixed.
A kind of step-down/up type power supply changeover device is characterized in that, comprising:
One inductance;
One first switch is connected between first end of the input of described power supply changeover device and described inductance;
One second switch is connected between first end and an earth terminal of described inductance;
One the 3rd switch is connected between second end and described earth terminal of described inductance;
One diode has an anode and connects second end of described inductance and the output that a negative electrode connects described power supply changeover device;
One control circuit, control described first, second, third and the switching of the 4th switch, and determine described power supply changeover device to operate in decompression mode, the first buck pattern, second buck pattern or the boost mode according to the load current on voltage on described input and the output and the described output;
Wherein, when described first and second buck pattern, the control of described first, second and third switch comprises (a) and closes described first switch, opens described second switch and close described the 3rd switch, (b) open described first switch, close described second switch and keep described the 3rd switch and close, and (c) keep described first switch opens, keep described second switch and close and open described the 3rd switch.
Aforesaid power supply changeover device, voltage and the multiplier value at described inductance two ends that load current determined described output on during less than one first critical value of wherein said control circuit on described input and output determines described power supply changeover device to operate in described decompression mode; The multiplier value at the described inductance two ends that load current determined on voltage on described input and output and the described output determines described power supply changeover device to operate in the described first buck pattern during greater than described first critical value and less than one second critical value; The multiplier value at the described inductance two ends that load current determined on voltage on described input and output and the described output determines described power supply changeover device to operate in the described second buck pattern during less than one the 3rd critical value and greater than described second critical value; The multiplier value at the described inductance two ends that load current determined on voltage on described input and output and the described output determines described power supply changeover device to operate in described boost mode during greater than described the 3rd critical value.
Aforesaid power supply changeover device, wherein said control circuit comprises:
One error amplifier produces a secondary signal according to one first signal and a reference voltage, and described first signal is the function of voltage on the described power supply changeover device output;
One frequency generator provides a first frequency and a second frequency;
One mode detector detects the input of described power supply changeover device and the voltage on the output and produces one the 3rd signal and operate in decompression mode, the first buck pattern, second buck pattern or the boost mode to determine described power supply changeover device;
One sawtooth generator provides one the 4th signal or one the 5th signal according to described the 3rd signal and first frequency;
One first comparator, more described secondary signal and described the 4th signal produce one the 6th signal;
One second comparator, more described secondary signal and described the 5th signal produce one the 7th signal;
One control logic circuit is according to the switching of described the 3rd, the 6th and the 7th signal and described first, second and third switch of first and second FREQUENCY CONTROL.
Aforesaid power supply changeover device, wherein said control logic circuit comprises:
One frequency eliminator produces one the 3rd frequency to described first frequency frequency elimination;
One first logical circuit produces one first control signal, second control signal and the 3rd control signal and the 4th control signal according to described the 6th signal, first frequency, second frequency, the 3rd frequency and one second reference voltage;
One first multiplexer is chosen the switching that one of them controls described first and second switch according to described three signals from the described first, second, third and the 4th control signal;
One second logical circuit produces one the 5th control signal, the 6th control signal, the 7th control signal and the 8th control signal according to described the 7th signal, first frequency, the 3rd frequency and one the 3rd reference voltage;
One second multiplexer is chosen the switching that one of them controls described the 3rd switch according to described the 3rd signal from described the 5th, the 6th, the 7th and the 8th control signal.
Aforesaid power supply changeover device, wherein said frequency eliminator comprise D type flip-flop.
Aforesaid power supply changeover device, wherein when described decompression mode, the switching cycle of described first and second switch is a period 1; The switching cycle of described first, second and third switch is a second round greater than the described period 1 when the described first buck pattern; The switching cycle of described first, second and third switch is a period 3 greater than the described period 1 when the described second buck pattern; The switching cycle of described the 3rd switch is a period 4 less than described second and third cycle when described boost mode.
Aforesaid power supply changeover device, wherein when the described first buck pattern, the responsibility cycle of described the 3rd switch is fixed.
Aforesaid power supply changeover device, wherein when the described second buck pattern, the responsibility cycle of described first and second switch is fixed.
A kind of control method of step-down/up type power supply changeover device, described power supply changeover device comprises an inductance, one first switch is connected between first end of the input of described power supply changeover device and described inductance, one diode has an anode and connects first end that an earth terminal and a negative electrode connect described inductance, one second switch is connected between second end and described earth terminal of described inductance, and one the 3rd switch be connected between the output of second end of described inductance and described power supply changeover device, it is characterized in that described control method comprises the following steps:
First step: the voltage and the load current on the described output that detect on described input and the output operate in decompression mode, the first buck pattern, second buck pattern or the boost mode to determine described power supply changeover device;
Second step: when described first and second buck pattern, the control of described first, second and third switch comprises:
(a) close described first switch, close described second switch, open described the 3rd switch;
(b) open described first switch, keep described second switch and close, keep described the 3rd switch opens;
(c) keep described first switch opens, open described second switch, close described the 3rd switch.
The step that aforesaid control method, the described power supply changeover device of wherein said decision operate in decompression mode, the first buck pattern, the second buck pattern or boost mode comprises:
When the multiplier value at the described inductance two ends that load current determined on voltage on described input and the output and the described output during, determine described power supply changeover device to operate in decompression mode less than one first critical value;
When on described input and the output with described output on the multiplier value at the described inductance two ends that load current determined during greater than described first critical value and less than one second critical value, determine described power supply changeover device to operate in the described first buck pattern;
When the multiplier value at the described inductance two ends that load current determined on voltage on described input and the output and the described output during, determine described power supply changeover device to operate in the described second buck pattern less than one the 3rd critical value and greater than described second critical value;
When the multiplier value at the described inductance two ends that load current determined on voltage on described input and the output and the described output during, determine described power supply changeover device to operate in described boost mode greater than described the 3rd critical value.
Aforesaid control method wherein more comprises:
The difference of amplifying between one first signal and the reference voltage produces a secondary signal, and described first signal is the function of voltage on the described output;
One first frequency and a second frequency are provided;
Operator scheme and described first frequency according to described power supply changeover device produce one the 3rd signal and one the 4th signal;
More described secondary signal and the 3rd signal produce one the 5th signal;
More described secondary signal and the 4th signal produce one the 6th signal;
Operator scheme, the described the 5th and the 6th signal, first frequency and second frequency according to described power supply changeover device are controlled described first, second and third switch.
Aforesaid control method, wherein when described decompression mode, the switching cycle of described first switch is a period 1; The switching cycle of described first, second and third switch is a second round greater than the described period 1 when the described first buck pattern; The switching cycle of described first, second and third switch is a period 3 greater than the described period 1 when the described second buck pattern; The switching cycle of described second and third switch is a period 4 less than described second and third cycle when described boost mode.
Aforesaid control method, wherein when the described first buck pattern, the responsibility cycle of described second and third switch is fixed.
Aforesaid control method, wherein when the described second buck pattern, the responsibility cycle of described first switch is fixed.
A kind of step-down/up type power supply changeover device is characterized in that, comprising:
One inductance;
One first switch is connected between first end of the input of described power supply changeover device and described inductance;
One diode has an anode and connects first end that an earth terminal and a negative electrode connect described inductance;
One second switch is connected between second end and described earth terminal of described inductance;
One the 3rd switch is connected between the output of second end of described inductance and described power supply changeover device;
One control circuit, control the switching of described first, second and third switch, and determine described power supply changeover device to operate in decompression mode, the first buck pattern, second buck pattern or the boost mode according to the load current on voltage on described input and the output and the described output;
Wherein, when described first and second buck pattern, the control of described first, second and third switch comprises (a) and closes described first switch, closes described second switch and open described the 3rd switch, (b) open described first switch, keep described second switch and close and keep described the 3rd switch opens, and (c) keep described first switch opens, open described second switch and close described the 3rd switch.
Aforesaid power supply changeover device, voltage and the multiplier value at described inductance two ends that load current determined described output on during less than one first critical value of wherein said control circuit on described input and output determines described power supply changeover device to operate in described decompression mode; The multiplier value at the described inductance two ends that load current determined on voltage on described input and output and the described output determines described power supply changeover device to operate in the described first buck pattern during greater than one first critical value and less than one second critical value; The multiplier value at the described inductance two ends that load current determined on voltage on described input and output and the described output determines described power supply changeover device to operate in the described second buck pattern during less than one the 3rd critical value and greater than described second critical value; The multiplier value at the described inductance two ends that load current determined on voltage on described input and output and the described output determines described power supply changeover device to operate in described boost mode during greater than described the 3rd critical value.
Aforesaid power supply changeover device, wherein said control circuit comprises:
One error amplifier produces a secondary signal according to one first signal and a reference voltage, and described first signal is the function of voltage on the described power supply changeover device output;
One frequency generator provides a first frequency and a second frequency;
One mode detector detects the input of described power supply changeover device and the voltage on the output and produces one the 3rd signal and operate in decompression mode, the first buck pattern, second buck pattern or the boost mode to determine described power supply changeover device;
One sawtooth generator provides one the 4th signal or one the 5th signal according to described the 3rd signal and first frequency;
One first comparator, more described secondary signal and described the 4th signal produce one the 6th signal;
One second comparator, more described secondary signal and described the 5th signal produce one the 7th signal;
One control logic circuit is according to the switching of described the 3rd, the 6th and the 7th signal and described first, second and third switch of first and second FREQUENCY CONTROL.
Aforesaid power supply changeover device, wherein said control logic circuit comprises:
One frequency eliminator produces one the 3rd frequency to described first frequency frequency elimination;
One first logical circuit produces one first control signal, second control signal, the 3rd control signal and the 4th control signal according to described the 6th signal, first frequency, second frequency, the 3rd frequency and one second reference voltage;
One first multiplexer is chosen the switching that one of them controls described first switch according to described three signals from the described first, second, third and the 4th control signal;
One second logical circuit produces one the 5th control signal, the 6th control signal, the 7th control signal and the 8th control signal according to described the 7th signal, first frequency, the 3rd frequency and one the 3rd reference voltage;
One second multiplexer is chosen the switching that one of them controls described second and third switch according to described the 3rd signal from described the 5th, the 6th, the 7th and the 8th control signal.
Aforesaid power supply changeover device, wherein said frequency eliminator comprise D type flip-flop.
Aforesaid power supply changeover device, wherein when described decompression mode, the switching cycle of described first switch is a period 1; The switching cycle of described first, second and third switch is a second round greater than the described period 1 when the described first buck pattern; The switching cycle of described first, second and third switch is a period 3 greater than the described period 1 when the described second buck pattern; The switching cycle of described second and third switch is a period 4 less than described second and third cycle when described boost mode.
Aforesaid power supply changeover device, wherein when the described first buck pattern, the responsibility cycle of described second and third switch is fixed.
42, power supply changeover device as claimed in claim 35 is characterized in that, when the described second buck pattern, the responsibility cycle of described first switch is fixed.
A kind of control method of step-down/up type power supply changeover device, described power supply changeover device comprises an inductance, one first switch is connected between first end of the input of described power supply changeover device and described inductance, one first diode has an anode and connects first end that an earth terminal and a negative electrode connect described inductance, one second switch is connected between second end and described earth terminal of described inductance, and one second diode have an anode and connect second end of described inductance and the output that a negative electrode connects described power supply changeover device, it is characterized in that described control method comprises the following steps:
First step: the voltage and the load current on the described output that detect on described input and the output operate in decompression mode, the first buck pattern, second buck pattern or the boost mode to determine described power supply changeover device;
Second step: when described first and second buck pattern, the control of described first and second switch comprises:
(a) close described first switch, close described second switch;
(b) open described first switch, keep described second switch and close;
(c) keep described first switch opens, open described second switch.
The step that aforesaid control method, the described power supply changeover device of wherein said decision operate in decompression mode, the first buck pattern, the second buck pattern or boost mode comprises:
When the multiplier value at the described inductance two ends that load current determined on voltage on described input and the output and the described output during, determine described power supply changeover device to operate in decompression mode less than one first critical value;
When the multiplier value at the described inductance two ends that load current determined on voltage on described input and the output and the described output during, determine described power supply changeover device to operate in the described first buck pattern greater than described first critical value and less than one second critical value;
When the multiplier value at the described inductance two ends that load current determined on voltage on described input and the output and the described output during, determine described power supply changeover device to operate in the described second buck pattern less than one the 3rd critical value and greater than described second critical value;
When the multiplier value at the described inductance two ends that voltage and load current determined on described input and the output during, determine described power supply changeover device to operate in described boost mode greater than described the 3rd critical value.
Aforesaid control method wherein more comprises:
The difference of amplifying between one first signal and the reference voltage produces a secondary signal, and described first signal is the function of voltage on the described output;
One first frequency and a second frequency are provided;
Operator scheme and described first frequency according to described power supply changeover device produce one the 3rd signal and one the 4th signal;
More described secondary signal and the 3rd signal produce one the 5th signal;
More described secondary signal and the 4th signal produce one the 6th signal;
Operator scheme, the described the 5th and the 6th signal, first frequency and described first and second switch of second frequency control according to described power supply changeover device.
Aforesaid control method, wherein when described decompression mode, the switching cycle of described first switch is a period 1; The switching cycle of described first and second switch is a second round greater than the described period 1 when the described first buck pattern; The switching cycle of described first and second switch is a period 3 greater than the described period 1 when the described second buck pattern; The switching cycle of described second switch is a period 4 less than described second and third cycle when described boost mode.
Aforesaid control method, wherein when the described first buck pattern, the responsibility cycle of described second switch is fixed.
Aforesaid control method, wherein when the described second buck pattern, the responsibility cycle of described first switch is fixed.
A kind of step-down/up type power supply changeover device is characterized in that, comprising:
One inductance;
One first switch is connected between first end of the input of described power supply changeover device and described inductance;
One first diode has an anode and connects first end that an earth terminal and a negative electrode connect described inductance;
One second switch is connected between second end and described earth terminal of described inductance;
One second diode has an anode and connects second end of described inductance and the output that a negative electrode connects described power supply changeover device;
One control circuit, control the switching of described first and second switch, and determine described power supply changeover device to operate in decompression mode, the first buck pattern, second buck pattern or the boost mode according to the load current on voltage on described input and the output and the described output;
Wherein, when described first and second buck pattern, the control of described first and second switch comprises (a) and closes described first switch and close described second switch, (b) open described first switch and keep described second switch and close, and (c) keep described first switch opens and open described second switch.
Aforesaid power supply changeover device, wherein said control circuit determines described power supply changeover device to operate in described decompression mode when the multiplier value at the described inductance two ends that load current determined on voltage on described input and the output and the described output during less than one first critical value; The multiplier value at the described inductance two ends that load current determined on voltage on described input and output and the described output determines described power supply changeover device to operate in the described first buck pattern during greater than described first critical value and less than one second critical value; The multiplier value at the described inductance two ends that load current determined on voltage on described input and output and the described output determines described power supply changeover device to operate in the described second buck pattern during less than one the 3rd critical value and greater than described second critical value; The multiplier value at the described inductance two ends that load current determined on voltage on described input and output and the described output determines described power supply changeover device to operate in described boost mode during greater than described the 3rd critical value.
Aforesaid power supply changeover device, wherein said control circuit comprises:
One error amplifier produces a secondary signal according to one first signal and a reference voltage, and described first signal is the function of voltage on the described power supply changeover device output;
One frequency generator provides a first frequency and a second frequency;
One mode detector detects the input of described power supply changeover device and the voltage on the output and produces one the 3rd signal and operate in decompression mode, the first buck pattern, second buck pattern or the boost mode to determine described power supply changeover device;
One sawtooth generator provides one the 4th signal or one the 5th signal according to described the 3rd signal and first frequency;
One first comparator, more described secondary signal and described the 4th signal produce one the 6th signal;
One second comparator, more described secondary signal and described the 5th signal produce one the 7th signal;
One control logic circuit is according to the switching of described the 3rd, the 6th and the 7th signal and described first and second switch of first and second FREQUENCY CONTROL.
Aforesaid power supply changeover device, wherein said control logic circuit comprises:
One frequency eliminator produces one the 3rd frequency to described first frequency frequency elimination;
One first logical circuit produces one first control signal, second control signal, the 3rd control signal and the 4th control signal according to described the 6th signal, first frequency, second frequency, the 3rd frequency and one the 3rd reference voltage;
One first multiplexer is chosen the switching that one of them controls described first switch according to described three signals from the described first, second, third and the 4th control signal;
One second logical circuit produces one the 5th control signal, the 6th control signal, the 7th control signal and the 8th control signal according to described the 7th signal, first frequency, the 3rd frequency and one the 3rd reference voltage;
One second multiplexer is chosen the switching that one of them controls described second switch according to described the 3rd signal from described the 5th, the 6th, the 7th and the 8th control signal.
Aforesaid power supply changeover device, wherein said frequency eliminator comprise D type flip-flop.
Aforesaid power supply changeover device, wherein when described decompression mode, the switching cycle of described first switch is a period 1; The switching cycle of described first and second switch is a second round greater than the described period 1 when the described first buck pattern; The switching cycle of described first and second switch is a period 3 greater than the described period 1 when the described second buck pattern; The switching cycle of described second switch is a period 4 less than described second and third cycle when described boost mode.
Aforesaid power supply changeover device, wherein when the described first buck pattern, the responsibility cycle of described second switch is fixed.
Aforesaid power supply changeover device, wherein when the described second buck pattern, the responsibility cycle of described first switch is fixed.
After adopting technique scheme, step-down/up type power supply changeover device of the present invention and control method thereof have the following advantages:
1. when power supply changeover device operates in the buck pattern,, and then reduce switch cost and conducting loss with new described at least two switches of transfer sequence control.
2. when power supply changeover device enters the buck pattern by decompression mode or boost mode, the switching cycle of described at least two switches is prolonged, with further minimizing switch cost, and consider that load current makes it put switch mode correct to the influence of buck responsibility cycle, so output voltage can be not influenced because of the change pattern.
Description of drawings
Fig. 1 is known step-down/up type power supply changeover device schematic diagram;
Fig. 2 is a first embodiment of the present invention schematic diagram;
Signal waveform when Fig. 3 operates in first pattern for power supply changeover device among Fig. 2;
Inductive current IL and switching sequence on the inductance L when Fig. 4 operates in first pattern for power supply changeover device among Fig. 2;
Signal waveform when Fig. 5 operates in second pattern for power supply changeover device among Fig. 2;
Inductive current IL and switching sequence on the inductance L when Fig. 6 operates in second pattern for power supply changeover device among Fig. 2;
Signal waveform when Fig. 7 operates in three-mode for power supply changeover device among Fig. 2;
Inductive current IL and switching sequence on the inductance L when Fig. 8 operates in three-mode for power supply changeover device among Fig. 2;
Signal waveform when Fig. 9 operates in four-mode for power supply changeover device among Fig. 2;
Inductive current IL and switching sequence on the inductance L when Figure 10 operates in four-mode for power supply changeover device among Fig. 2;
Figure 11 is the mode switch figure of power supply changeover device among Fig. 2;
Figure 12 is the embodiment schematic diagram of control logic circuit among Fig. 2;
Figure 13 is a second embodiment of the present invention schematic diagram;
Figure 14 is a third embodiment of the present invention schematic diagram;
Figure 15 is a fourth embodiment of the present invention schematic diagram;
Figure 16 is the embodiment schematic diagram of mode detector.
Among the figure, 10, power supply changeover device 12, power stage 14, control circuit 16, control logic circuit 18, comparator 20, comparator 22, sawtooth generator 24, error amplifier 30, power supply changeover device 32, power stage 34, control circuit 36, control logic circuit 3602, D type flip-flop 3604, logical circuit 3606, multiplexer 3608, logical circuit 3610, multiplexer 38, mode detector 3802, current source 3804, operational amplifier 3806, current source 3808, comparator 3810, comparator 3812, comparator 40, comparator 42, comparator 44, sawtooth generator 46, error amplifier 48, frequency generator 50, the waveform 52 of sawtooth signal SAW12, the waveform 54 of error signal VEA, the waveform 56 of signal PWM1, the waveform 58 of frequency Clk_buck, the waveform 60 of frequency Clk_boost, the waveform 62 of control signal VA, the waveform 64 of control signal VB, the waveform 66 of control signal VC, the waveform 68 of control signal VD, the waveform 70 of sawtooth signal SAW12, the waveform 72 of error signal VEA, the waveform 74 of signal PWM1, the waveform 76 of frequency Clk_buck, the waveform 78 of frequency Clk_boost, the waveform 80 of control signal VA, the waveform 82 of control signal VB, the waveform 84 of control signal VC, the waveform 86 of control signal VD, the waveform 88 of sawtooth signal SAW34, the waveform 90 of error signal VEA, the waveform 92 of signal PWM2, the waveform 94 of frequency Clk_buck, the waveform 96 of frequency Clk_boost, the waveform 98 of control signal VA, the waveform 100 of control signal VB, the waveform 102 of control signal VC, the waveform 104 of control signal VD, the waveform 106 of sawtooth signal SAW34, the waveform 108 of error signal VEA, the waveform 110 of signal PWM2, the waveform 112 of frequency Clk_buck, the waveform 114 of frequency Clk_boost, the waveform 116 of control signal VA, the waveform 118 of control signal VB, the waveform 120 of control signal VC, the waveform 130 of control signal VD, power supply changeover device 132, power stage 140, power supply changeover device 142, power stage 150, power supply changeover device 152, power stage.
Embodiment
Below in conjunction with embodiment and accompanying drawing thereof the present invention is illustrated further.
Now see also Fig. 2, Fig. 2 shows the first embodiment of the present invention.As shown in the figure, described in step-down/up type power supply changeover device 30, control circuit 34 output control signal VA, VB, VC and VD driving power level 32, input voltage vin is converted to output voltage V out, resistance R 1 and R2 pressure-dividing output voltage Vout produce feedback signal VFB and give control circuit 34.In power stage 32, switch SW 1 is connected between input voltage vin and the inductance L, and switch SW 2 is connected between inductance L and the earth terminal GND, and switch SW 3 is connected between inductance L and the earth terminal GND, and switch SW 4 is connected between inductance L and the output voltage V out.Because the responsibility cycle of whole system is not only relevant with input voltage and output voltage, load current also can influence the size of responsibility cycle, so the switching point of pattern also must be taken into account the factor of load current.In control circuit 34, mode detector 38 detects input voltage vin, output voltage V out and load current Iload produce mode select signal S[3:0] to determine the operator scheme of power supply changeover device 30, error amplifier 46 produces error signal VEA according to reference voltage Vref and feedback signal VFB, frequency generator 48 provides frequency Clk_boost and Clk_buck, frequency Clk_boost and Clk_buck have fixing period T s and fixing responsibility cycle, sawtooth generator 44 is according to frequency Clk_boost and mode select signal S[3:0] sawtooth signal SAW12 and SAW34 be provided, comparator 40 comparison error signal VEA and sawtooth signal SAW12 produce signal PWM1, comparator 42 comparison error signal VEA and sawtooth signal SAW34 produce signal PWM2, and control logic circuit 36 is according to signal PWM1 and PWM2, mode select signal S[3:0] and frequency Clk_boost and Clk_buck generation control signal VA, VB, VC and VD diverter switch SW1, SW2, SW3 and SW4 are to be converted to input voltage vin output voltage V out.
Described power supply changeover device 30 may operate in four kinds of patterns, and when the multiplier value at the inductance two ends that input voltage vin, output voltage V out and load current Iload are determined during less than first critical value, power supply changeover device 30 operates in first pattern.Signal waveform when Fig. 3 display power supply transducer 30 operates in first pattern, wherein waveform 50 is sawtooth signal SAW12, waveform 52 is error signal VEA, waveform 54 is signal PWM1, and waveform 56 is frequency Clk_buck, and waveform 58 is frequency Clk_boost, waveform 60 is control signal VA, waveform 62 is control signal VB, and waveform 64 is control signal VC, and waveform 66 is control signal VD.Inductive current IL and switching sequence on the inductance L when Fig. 4 display power supply transducer 30 operates in first pattern.First pattern is simple decompression mode, at time t1 to t2, control signal VA, VB, VC and VD are low level, shown in waveform 60,62,64 and 66, because switch SW 1 and SW4 are PMOS and switch SW 2 and SW3 are NMOS, switch SW 2 and SW3 close (turn off) so switch SW 1 and SW4 open (turn on), be defined as tAD1 during this period of time, in time tAD1, charging makes inductive current IL rise to input voltage vin to inductance L, as shown in Figure 4.At time t2 to t3, control signal VA and VB are high levle and control signal VC and VD are low level, and switch SW 1 and SW3 close so switch SW 2 and SW4 open, and this time is defined as tBD1, and in time tBD1, the inductance L discharge makes inductive current IL descend.In first pattern, the cycle of the switching cycle of switch SW 1 and SW2 and inductive current IL is Ts, and the step-down responsibility cycle is the responsibility cycle ratio of switch SW 1 than Kbuck1.
When the multiplier value at the inductance two ends that input voltage vin, output voltage V out and load current Iload are determined greater than first critical value and less than 1 the time, power supply changeover device 30 operates in second pattern.Signal waveform when Fig. 5 display power supply transducer 30 operates in second pattern, wherein waveform 68 is sawtooth signal SAW12, waveform 70 is error signal VEA, waveform 72 is signal PWM1, and waveform 74 is frequency Clk_buck, and waveform 76 is frequency Clk_boost, waveform 78 is control signal VA, waveform 80 is control signal VB, and waveform 82 is control signal VC, and waveform 84 is control signal VD.Inductive current IL and switching sequence when Fig. 6 display power supply transducer 30 operates in second pattern.Second pattern is the buck pattern, at time t4 to t5, control signal VA and VB are high levle and control signal VC and VD are low level, switch SW 2 and SW4 open so switch SW 1 and SW3 close, be defined as tBD2 during this period of time, at time t5 to t6, control signal VA, VB, VC and VD are low level, switch SW 2 and SW3 close so switch SW 1 and SW4 open, be defined as tAD2 during this period of time, at time t6 to t7, control signal A and B are low level and control signal C and D are high levle, switch SW 2 and SW4 close so switch SW 1 and SW3 open, and are defined as tAC1 during this period of time.In second pattern, the cycle of the switching cycle of switch SW 1, SW2, SW3 and SW4 and inductive current IL is 2Ts.With reference to Fig. 6, each cycle of inductive current IL comprises step-down and boost operations, in second pattern, the responsibility cycle of switch SW 3 and SW4 is determined by frequency Clk_boost, so switch SW 3 and SW4 have fixing responsibility cycle, therefore, the responsibility cycle of boosting during boost operations is fixed than Kboost1, can allow output voltage V out stable by the step-down responsibility cycle that is adjusted at during the reduced pressure operation than Kbuck2.
When the multiplier value at the inductance two ends that input voltage vin, output voltage V out and load current Iload are determined less than second critical value and greater than 1 the time, power supply changeover device 30 operates in three-mode.Signal waveform when Fig. 7 display power supply transducer 30 operates in three-mode, wherein waveform 86 is sawtooth signal SAW34, waveform 88 is error signal VEA, waveform 90 is signal PWM2, and waveform 92 is frequency Clk_buck, and waveform 94 is frequency Clk_boost, waveform 96 is control signal VA, waveform 98 is control signal VB, and waveform 100 is control signal VC, and waveform 102 is control signal VD.Inductive current IL and switching sequence when Fig. 8 display power supply transducer 30 operates in three-mode.Three-mode is the buck pattern, at time t8 to t9, control signal VA and VB are high levle and control signal VC and VD are low level, switch SW 2 and SW4 open so switch SW 1 and SW3 close, be defined as tBD3 during this period of time, at time t9 to t10, control signal VA, VB, VC and VD are low level, switch SW 2 and SW3 close so switch SW 1 and SW4 open, be defined as tAD3 during this period of time, at time t10 to t11, control signal A and B are low level and control signal C and D are high levle, switch SW 2 and SW4 close so switch SW 1 and SW3 open, and are defined as tAC2 during this period of time.In three-mode, the cycle of the switching cycle of switch SW 1, SW2, SW3 and SW4 and inductive current IL is 2Ts.With reference to Fig. 8, each cycle of inductive current IL comprises step-down and boost operations, in three-mode, the responsibility cycle of switch SW 1 and SW2 is determined by frequency Clk_buck, so the responsibility cycle of switch SW 1 and SW2 is fixed, therefore, the step-down responsibility cycle during reduced pressure operation is fixed than Kbuck3, can allow output voltage V out stable by the responsibility cycle of boosting that is adjusted at during the boost operations than Kboost2.
When the multiplier value at the inductance two ends that input voltage vin, output voltage V ou and load current Iload are determined greater than second critical value, power supply changeover device 30 operates in four-mode.The signal waveform of Fig. 9 display power supply transducer 30 behaviour's parts when four-mode, wherein waveform 104 is sawtooth signal SAW34, waveform 106 is error signal VEA, waveform 108 is signal PWM2, and waveform 110 is frequency Clk_buck, and waveform 112 is frequency Clk_boost, waveform 114 is control signal VA, waveform 116 is control signal VB, and waveform 118 is control signal VC, and waveform 120 is control signal VD.Inductive current IL and switching sequence when Figure 10 display power supply transducer 30 operates in four-mode.Four-mode is simple boost mode, at time t12 to t13, control signal VA and VB are low level and control signal VC and VD are high levle, switch SW 2 and SW4 close so switch SW 1 and SW3 open, be defined as tAC3 during this period of time, at time t13 to t14, control signal VA, VB, VC and VD are low level, switch SW 2 and SW3 close so switch SW 1 and SW4 open, and are defined as tAD4 during this period of time.In four-mode, the cycle of the switching cycle of switch SW 3 and SW4 and inductive current IL is Ts, and the responsibility cycle of boosting is the responsibility cycle ratio of switch SW 3 than Kboost3.
When power supply changeover device 30 operates in the buck pattern, the transfer sequence of switch is opened switch SW 2 and SW4 and off switch SW1 and SW3 for (1), (2) open switch SW 1 and SW4 and off switch SW2 and SW3, (3) open switch SW 1 and SW3 and off switch SW2 and SW4, compare with known techniques, in the circulation of identical time, the switch switching times of power supply changeover device 30 is less, and when the operator scheme of power supply changeover device 30 enters the buck pattern by decompression mode or boost mode, the switching cycle of switch will be extended for 2Ts by Ts, so can reduce switch cost.Moreover the duration that this new switching sequence can allow inductance L be connected with the output end vo ut of power supply changeover device 30 prolongs, so can reduce the conducting loss.
Utilize weber balance (voltage second balance) principle can derive relation between input voltage vin, output voltage V out and the load current Iload of power supply changeover device 30 under four kinds of patterns.With reference to Fig. 4, suppose that the cross-pressure on each switch SW 1, SW2, SW3 and the SW4 all is Vsw, when transducer operated in first pattern, the pass between the cross-pressure Vsw of input voltage vin, output voltage V out and switch was
Vin-2Vsw/ (tAD1/Ts)=Vout/ (tAD1/Ts) formula 1
With reference to Fig. 6, when second pattern, the pass between the cross-pressure Vsw of input voltage vin, output voltage V out and switch is
Vin-4Vsw/(Ts+tAD2_1)
=Vout[(Ts+tAD2_2)/(Ts+tAD2_1)]
=Vout[(2-Kboost1) Ts/ (Ts+tAD2_1)] formula 2
With reference to Fig. 8, when three-mode, the pass between the cross-pressure Vsw of input voltage vin, output voltage V out and switch is
Vin-4Vsw/(Ts+tAD3_1)
=Vout[(Ts+tAD3_2)/(Ts+tAD3_1)]
=Vout[(Ts+tAD3_2)/(1+Kbuck3) Ts] formula 3
With reference to Figure 10, when four-mode, the pass between the cross-pressure Vsw of input voltage vin, output voltage V out and switch is
Vin-2Vsw=Vout (1-tAC3/Ts) formula 4
For the nonlinear problem that prevents sawtooth signal SAW12 and SAW34 makes output voltage V out to stablize, be respectively K1 and K2 so limit the maximum liability cycle of step-down and the minimum responsibility cycle of boosting, so that input voltage vin near or when equaling output voltage V out, can allow output voltage V out stable.The mode switch figure of Figure 11 display power supply transducer 30 is from formula 1 to formula 4 and the critical value K1 that sets and the K2 mode switch that can obtain power supply changeover device 30.When power supply changeover device 30 operates in first pattern,,, input voltage vin makes that power supply changeover device 30 switched to second pattern when multiplier value at inductance L two ends equaled critical value A1 if continuing decline with reference to Figure 11.When power supply changeover device 30 operates in second pattern,,, input voltage vin makes that power supply changeover device 30 switched to three-mode when the multiplier value at inductance L two ends equaled critical value A2 if continuing decline with reference to Figure 11.When power supply changeover device 30 operates in three-mode,,, input voltage vin makes that power supply changeover device 30 switched to four-mode when the multiplier value at inductance L two ends equaled critical value A3 if continuing decline with reference to Figure 11.When power supply changeover device 30 operates in four-mode,,, input voltage vin makes that power supply changeover device 30 switched to three-mode when the multiplier value at inductance L two ends equaled critical value A3 if continuing rising with reference to Figure 11 and formula 4.When power supply changeover device 30 operates in three-mode,, input voltage vin makes that power supply changeover device 30 switched to second pattern when multiplier value at inductance L two ends equaled critical value A2 if continuing rising.When power supply changeover device 30 operated in second pattern, if input voltage vin continue to rise, power supply changeover device 30 switched to first pattern when making the multiplier value of inductance two ends L equal critical value A1.
The embodiment of control logic circuit 36 in Figure 12 displayed map 2, wherein D type flip-flop 3602 as frequency eliminator in order to frequency Clk_boost frequency elimination is produced frequency CLK2 and CLK2B, logical circuit 3604 is according to signal PWM1, frequency Clk_boost, the current potential of CLK2 and Clk_buck and earth terminal GND produces control signal S1, S2, S3 and S4, multiplexer 3606 is according to mode select signal S[3:0] from control signal S4, S3, choose one of them among S2 and the S1 as control signal VA and VB, logical circuit 3608 is according to the current potential of earth terminal GND, frequency CLK2B and Clk_boost and signal PWM2 produce control signal S5, S6, S7 and S8, multiplexer 3610 is according to mode select signal S[3:0] from control signal S8, S7, choose one of them among S6 and the S5 as control signal VC and VD.
Figure 13 shows the second embodiment of the present invention, in step-down/up type power supply changeover device 130, control circuit 34 driving power levels 132 are to be converted to input voltage vin output voltage V out, and resistance R 1 and R2 pressure-dividing output voltage Vout produce feedback signal VFB and give control circuit 34.In power stage 132, switch SW 1 is connected between input voltage vin and the inductance L, and switch SW 2 is connected between inductance L and the earth terminal GND, and switch SW 3 is connected between inductance L and the earth terminal GND, and diode D1 is connected between inductance L and the output voltage V out.Control circuit 34 comprises control logic circuit 36, mode detector 38, comparator 40 and 42, sawtooth generator 44, error amplifier 46 and frequency generator 48 equally, and control logic circuit 36 is according to signal PWM1 and PWM2, mode select signal S[3:0] and frequency Clk_boost and Clk_buck produce control signal VA, VB and VC diverter switch SW1, SW2 and SW3 input voltage vin is converted to output voltage V out.
When power supply changeover device 130 operates in the buck pattern, the transfer sequence of its switch is opened switch SW 2 and off switch SW1 and SW3 for (1), (2) open switch SW 1 and off switch SW2 and SW3, (3) open switch SW 1 and SW3 and off switch SW2, repeating step (1) is to (3) afterwards, wherein, work as input voltage vin, the responsibility cycle that output voltage V out and load current Iload are determined is greater than first critical value and less than 1, the responsibility cycle of switch SW 3 is fixed, work as input voltage vin, the responsibility cycle that output voltage V out and load current Iload are determined is less than second critical value and greater than 1, the responsibility cycle of switch SW 1 and SW2 is fixed, and when the operator scheme of power supply changeover device 130 enters the buck pattern by decompression mode or boost mode, the switching cycle of switch will be extended for 2Ts by Ts.
Figure 14 shows the third embodiment of the present invention, in step-down/up type power supply changeover device 140, control circuit 34 driving power levels 142 are to be converted to input voltage vin output voltage V out, and resistance R 1 and R2 pressure-dividing output voltage Vout produce feedback signal VFB and give control circuit 34.In power stage 142, switch SW 1 is connected between input voltage vin and the inductance L, and diode D2 is connected between inductance L and the earth terminal GND, and switch SW 3 is connected between inductance L and the earth terminal GND, and switch SW 4 is connected between inductance L and the output voltage V out.Control circuit 34 isotype control logic circuit 36, mode detector 38, comparator 40 and 42, sawtooth generator 44, error amplifier 46 and the frequency generators 48 of comprising, control logic circuit 36 is according to signal PWM1 and PWM2, mode select signal S[3:0] and frequency Clk_boost and Clk_buck produce control signal VA, VC and VD diverter switch SW1, SW3 and SW4 input voltage vin is converted to output voltage V out.
When power supply changeover device 140 operates in the buck pattern, the transfer sequence of its switch is opened switch SW 4 and off switch SW1 and SW3 for (1), (2) open switch SW 1 and SW4 and off switch SW3, (3) open switch SW 1 and SW3 and off switch SW4, repeating step (1) is to (3) afterwards, wherein, work as input voltage vin, the responsibility cycle that output voltage V out and load current Iload are determined is greater than first critical value and less than 1, the responsibility cycle of switch SW 3 and SW4 is fixed, work as input voltage vin, the responsibility cycle that output voltage V out and load current Iload are determined is less than second critical value and greater than 1, the responsibility cycle of switch SW 1 is fixed, and when the operator scheme of power supply changeover device 140 enters the buck pattern by decompression mode or boost mode, the switching cycle of switch will be extended for 2Ts by Ts.
Figure 15 shows the fourth embodiment of the present invention, in step-down/up type power supply changeover device 150, control circuit 34 driving power levels 152 are to be converted to input voltage vin output voltage V out, and resistance R 1 and R2 pressure-dividing output voltage Vout produce feedback signal VFB and give control circuit 34.In power stage 152, switch SW 1 is connected between input voltage vin and the inductance L, and diode D3 is connected between inductance L and the earth terminal GND, and switch SW 3 is connected between inductance L and the earth terminal GND, and diode D4 is connected between inductance L and the output voltage V out.Control circuit 34 isotype control logic circuit 36, mode detector 38, comparator 40 and 42, sawtooth generator 44, error amplifier 46 and the frequency generators 48 of comprising, control logic circuit 36 is according to signal PWM1 and PWM2, mode select signal S[3:0] and frequency Clk_boost and Clk_buck produce control signal VA and VC diverter switch SW1 and SW3 so that input voltage Vi n is converted to output voltage V out.
When power supply changeover device 150 operates in the buck pattern, the transfer sequence of its switch is (1) off switch SW1 and SW3, (2) open switch SW 1 and off switch SW3, (3) open switch SW 1 and SW3, repeating step (1) is to (3) afterwards, wherein, work as input voltage vin, the responsibility cycle that output voltage V out and load current Iload are determined is greater than first critical value and less than 1, the responsibility cycle of switch SW 3 is fixed, work as input voltage vin, the responsibility cycle that output voltage V out and load current Iload are determined is less than second critical value and greater than 1, the responsibility cycle of switch SW 1 is fixed, and when the operator scheme of power supply changeover device 150 enters the buck pattern by decompression mode or boost mode, the switching cycle of switch will be extended for 2Ts by Ts.
The embodiment of Figure 16 display mode detector 38, in mode detector 38, when switch SW 1 was opened, switch MP1 also opened simultaneously, so voltage Vb is (Vin-Vsw-Ib * R3), wherein voltage Vsw is directly proportional with load current Iload, operational amplifier 3804 is locked in voltage Vb and Va with on the position surely, and the electric current I a that therefore flows through resistance R 4 is (Ib+Vsw/R4), and design current source 3802 and 3806 equates, make the flow through electric current I c of resistance R 5 be (Vsw/R4), therefore can push away voltage
VDEC=Vin-Ia×R4-Ic×R5
=Vin-Ib×R4-Vsw-(R5/R4)×Vsw
=Vin-(1+R5/R4) Vsw-Ib * R4 formula 5
Because (Ib's * R4) can design is relatively little, so voltage
Formula 6
By formula 6 as can be known, can regulation voltage VDEC by the ratio of adjusting resistance R 5 and R4, then comparator 3808,3810 and 3812 compare respectively (M1 * Vout), (M2 * Vout) and (M3 * Vout) and voltage VDEC, logical circuit 3814 produces mode select signal S[3:0 according to the output of comparator 3808,3810 and 3812].
Above embodiment is only for the usefulness that the present invention is described, but not limitation of the present invention, person skilled in the relevant technique under the situation that does not break away from the spirit and scope of the present invention, can also be made various conversion or variation.Therefore, all technical schemes that are equal to also should belong to category of the present invention, should be limited by each claim.

Claims (56)

1.一种升降压式电源转换器的控制方法,所述电源转换器包含一电感,一第一开关连接在所述电源转换器的输入端及所述电感的第一端之间,一第二开关连接在所述电感的第一端及一接地端之间,一第三开关连接在所述电感的第二端及所述接地端之间,以及一第四开关连接在所述电感的第二端及所述电源转换器的输出端之间,其特征在于所述控制方法包括下列步骤:1. A control method for a buck-boost power converter, the power converter includes an inductor, a first switch is connected between the input end of the power converter and the first end of the inductor, a A second switch is connected between the first terminal of the inductor and a ground terminal, a third switch is connected between the second terminal of the inductor and the ground terminal, and a fourth switch is connected between the inductor Between the second end of the power converter and the output end of the power converter, it is characterized in that the control method includes the following steps: 第一步骤:检测所述输入端及输出端上的电压以及在所述输出端上的负载电流以决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式;The first step: detecting the voltage on the input terminal and the output terminal and the load current on the output terminal to determine the operation of the power converter in the buck mode, the first buck-boost mode, and the second buck-boost mode mode or boost mode; 第二步骤:在所述第一及第二升降压模式时,所述第一、第二、第三及第四开关的控制包含:The second step: in the first and second buck-boost modes, the control of the first, second, third and fourth switches includes: (a)关闭所述第一开关,打开所述第二开关,关闭所述第三开关,打开所述第四开关;(a) closing the first switch, opening the second switch, closing the third switch, and opening the fourth switch; (b)打开所述第一开关,关闭所述第二开关,维持所述第三开关关闭,维持所述第四开关打开;(b) opening the first switch, closing the second switch, keeping the third switch closed, and keeping the fourth switch open; (c)维持所述第一开关打开,维持所述第二开关关闭,打开所述第三开关,关闭所述第四开关。(c) keeping the first switch open, keeping the second switch closed, opening the third switch, and closing the fourth switch. 2.如权利要求1所述的控制方法,其特征在于,所述决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式的步骤包括下列步骤:2. The control method according to claim 1, wherein the step of determining whether the power converter operates in a buck mode, a first buck-boost mode, a second buck-boost mode or a boost mode comprises Follow these steps: 第一步骤:当所述输入端及输出端上的电压与负载电流所决定出的所述电感两端的倍率值小于一第一临界值,决定所述电源转换器操作在降压模式;Step 1: When the multiplier value at both ends of the inductor determined by the voltage on the input terminal and the output terminal and the load current is smaller than a first critical value, determine that the power converter operates in a step-down mode; 第二步骤:当所述输入端及输出端上的电压与负载电流所决定出的所述电感两端的倍率值大于所述第一临界值且小于一第二临界值,决定所述电源转换器操作在所述第一升降压模式;Step two: determine the power converter when the multiplier value at both ends of the inductance determined by the voltage on the input terminal and the output terminal and the load current is greater than the first critical value and smaller than a second critical value operating in said first buck-boost mode; 第三步骤:当所述输入端及输出端上的电压与负载电流所决定出的所述电感两端的倍率值小于一第三临界值且大于所述第二临界值,决定所述电源转换器操作在所述第二升降压模式;Step 3: determine the power converter when the multiplier value at both ends of the inductance determined by the voltage on the input terminal and the output terminal and the load current is less than a third critical value and greater than the second critical value operating in said second buck-boost mode; 第四步骤:当所述输入端及输出端上的电压与负载电流所决定出的所述电感两端的倍率值大于所述第三临界值时,决定所述电源转换器操作在所述升压模式。Step 4: When the multiplier value at both ends of the inductor determined by the voltage on the input terminal and the output terminal and the load current is greater than the third critical value, determine that the power converter operates at the boost voltage model. 3.如权利要求1所述的控制方法,其特征在于,更包括:3. The control method according to claim 1, further comprising: 放大一第一信和及一参考电压之间的差值产生一第二信号,所述第一信号为所述输出端上电压的函数;amplifying a difference between a first signal sum and a reference voltage to generate a second signal, said first signal being a function of the voltage at said output terminal; 提供一第一频率及一第二频率;providing a first frequency and a second frequency; 根据所述电源转换器的操作模式及所述第一频率产生一第三信号及一第四信号;generating a third signal and a fourth signal according to the operation mode of the power converter and the first frequency; 比较所述第二信号及第三信号产生一第五信号;comparing the second signal and the third signal to generate a fifth signal; 比较所述第二信号及第四信号产生一第六信号;comparing the second signal and the fourth signal to generate a sixth signal; 根据所述电源转换器的操作模式、所述第五及第六信号、第一频率及第二频率控制所述第一、第二、第三及第四开关。The first, second, third and fourth switches are controlled according to the operating mode of the power converter, the fifth and sixth signals, the first frequency and the second frequency. 4.如权利要求1所述的控制方法,其特征在于,在所述降压模式时,所述第一及第二开关的切换周期为一第一周期;在所述第一升降压模式时所述第一、第二、第三及第四开关的切换周期为一大于所述第一周期的第二周期;在所述第二升降压模式时所述第一、第二、第三及第四开关的切换周期为一大于所述第一周期的第三周期;在所述升压模式时所述第三及第四开关的切换周期为一小于所述第二及第三周期的第四周期。4. The control method according to claim 1, wherein in the buck mode, the switching period of the first and second switches is a first period; in the first buck-boost mode The switching period of the first, second, third and fourth switches is a second period greater than the first period; in the second buck-boost mode, the first, second and fourth switches The switching period of the third and fourth switches is a third period greater than the first period; in the boost mode, the switching period of the third and fourth switches is a period shorter than the second and third period of the fourth cycle. 5.如权利要求1所述的控制方法,其特征在于,在所述第一升降压模式时,所述第三及第四开关的责任周期固定。5. The control method according to claim 1, wherein in the first buck-boost mode, duty periods of the third and fourth switches are fixed. 6.如权利要求1所述的控制方法,其特征在于,在所述第二升降压模式时,所述第一及第二开关的责任周期固定。6. The control method according to claim 1, wherein in the second buck-boost mode, duty periods of the first and second switches are fixed. 7.一种升降压式电源转换器,其特征在于,包括:7. A buck-boost power converter, characterized in that it comprises: 一电感;an inductance; 一第一开关,连接在所述电源转换器的输入端及所述电感的第一端之间;a first switch connected between the input terminal of the power converter and the first terminal of the inductor; 一第二开关,连接在所述电感的第一端及一接地端之间;a second switch connected between the first terminal of the inductor and a ground terminal; 一第三开关,连接在所述电感的第二端及所述接地端之间;a third switch connected between the second terminal of the inductor and the ground terminal; 一第四开关,连接在所述电感的第二端及所述电源转换器的输出端之间;a fourth switch connected between the second end of the inductor and the output end of the power converter; 一控制电路,控制所述第一、第二、第三及第四开关的切换,并根据所述输入端及输出端上的电压以及所述输出端上的负载电流决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式;a control circuit, controlling switching of the first, second, third and fourth switches, and determining the operation of the power converter according to the voltage on the input terminal and the output terminal and the load current on the output terminal In buck mode, first buck-boost mode, second buck-boost mode or boost mode; 其中,在所述第一及第二升降压模式时,所述第一、第二、第三及第四开关的控制包含(a)关闭所述第一开关、打开所述第二开关、关闭所述第三开关及打开所述第四开关,(b)打开所述第一开关、关闭所述第二开关、维持所述第三开关关闭及维持所述第四开关打开,以及(c)维持所述第一开关打开、维持所述第二开关关闭、打开所述第三开关及关闭所述第四开关。Wherein, in the first and second buck-boost modes, the control of the first, second, third and fourth switches includes (a) closing the first switch, opening the second switch, closing the third switch and opening the fourth switch, (b) opening the first switch, closing the second switch, keeping the third switch closed and keeping the fourth switch open, and (c ) maintain the first switch open, maintain the second switch closed, open the third switch, and close the fourth switch. 8.如权利要求7所述的电源转换器,其特征在于,所述控制电路在所述输入端及输出端上的电压与所述负载电流所决定出的所述电感两端的倍率值小于一第一临界值时,决定所述电源转换器操作在所述降压模式;在所述输入端及输出端上的电压与所述负载电流所决定出的所述电感两端的倍率值大于所述第一临界值且小于一第二临界值时,决定所述电源转换器操作在所述第一升降压模式;在所述输入端及输出端上的电压与所述负载电流所决定出的所述电感两端的倍率值小于一第三临界值且大于所述第二临界值时,决定所述电源转换器操作在所述第二升降压模式;在所述输入端及输出端上的电压与负载电流所决定出的所述电感两端的倍率值大于所述第三临界值时,决定所述电源转换器操作在所述升压模式。8 . The power converter according to claim 7 , wherein the voltage at the input terminal and the output terminal of the control circuit and the load current determine the multiplier value of both ends of the inductance to be less than one. When the first critical value is reached, it is determined that the power converter operates in the step-down mode; the multiplier value at both ends of the inductor determined by the voltage on the input terminal and the output terminal and the load current is greater than the When the first critical value is less than a second critical value, it is determined that the power converter operates in the first buck-boost mode; the voltage on the input terminal and the output terminal is determined by the load current When the multiplier value at both ends of the inductance is less than a third critical value and greater than the second critical value, it is determined that the power converter operates in the second buck-boost mode; When the multiplier value at both ends of the inductor determined by the voltage and the load current is greater than the third critical value, it is determined that the power converter operates in the boost mode. 9.如权利要求7所述的电源转换器,其特征在于,所述控制电路包括:9. The power converter according to claim 7, wherein the control circuit comprises: 一误差放大器,根据一第一信号及一参考电压产生一第二信号,所述第一信号为所述电源转换器输出端上电压的函数;an error amplifier generating a second signal based on a first signal and a reference voltage, the first signal being a function of the voltage at the output of the power converter; 一频率产生器,提供一第一频率及一第二频率;a frequency generator providing a first frequency and a second frequency; 一模式检测器,检测所述电源转换器的输入端及输出端上的电压产生一第三信号以决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式;A mode detector, detecting the voltage on the input end and the output end of the power converter to generate a third signal to determine whether the power converter is operating in the buck mode, the first buck-boost mode, the second buck-boost mode mode or boost mode; 一锯齿波产生器,根据所述第三信号及第一频率提供一第四信号或一第五信号;a sawtooth wave generator, providing a fourth signal or a fifth signal according to the third signal and the first frequency; 一第一比较器,比较所述第二信号及所述第四信号产生一第六信号;a first comparator, comparing the second signal and the fourth signal to generate a sixth signal; 一第二比较器,比较所述第二信号及所述第五信号产生一第七信号;a second comparator, comparing the second signal and the fifth signal to generate a seventh signal; 一控制逻辑电路,根据所述第三、第六及第七信号以及第一及第二频率控制所述第一、第二、第三及第四开关的切换。A control logic circuit controls switching of the first, second, third and fourth switches according to the third, sixth and seventh signals and the first and second frequencies. 10.如权利要求9所述的电源转换器,其特征在于,所述控制逻辑电路包括:10. The power converter according to claim 9, wherein the control logic circuit comprises: 一除频器,对所述第一频率除频产生一第三频率;a frequency divider that divides the first frequency to generate a third frequency; 一第一逻辑电路,根据所述第六信号、第一频率、第二频率、第三频率及一第二参考电压产生一第一控制信号、第二控制信号、第三控制信号及第四控制信号;A first logic circuit, generating a first control signal, a second control signal, a third control signal and a fourth control signal according to the sixth signal, the first frequency, the second frequency, the third frequency and a second reference voltage Signal; 一第一多任务器,根据所述三信号从所述第一、第二、第三及第四控制信号中选取其中之一来控制所述第一及第二开关的切换;A first multiplexer, selecting one of the first, second, third and fourth control signals according to the three signals to control switching of the first and second switches; 一第二逻辑电路,根据所述第七信号、第一频率、第三频率及一第三参考电压产生一第五控制信号、第六控制信号、第七控制信号及第八控制信号;A second logic circuit, generating a fifth control signal, a sixth control signal, a seventh control signal and an eighth control signal according to the seventh signal, the first frequency, the third frequency and a third reference voltage; 一第二多任务器,根据所述第三信号从所述第五、第六、第七及第八控制信号中选取其中之一来控制所述第三及第四开关的切换。A second multiplexer, selecting one of the fifth, sixth, seventh and eighth control signals according to the third signal to control switching of the third and fourth switches. 11.如权利要求10所述的电源转换器,其特征在于,所述除频器包括D型正反器。11. The power converter according to claim 10, wherein the frequency divider comprises a D-type flip-flop. 12.如权利要求7所述的电源转换器,其特征在于,在所述降压模式时,所述第一及第二开关的切换周期为一第一周期;在所述第一升降压模式时所述第一、第二、第三及第四开关的切换周期为一大于所述第一周期的第二周期;在所述第二升降压模式时所述第一、第二、第三及第四开关的切换周期为一大于所述第一周期的第三周期;在所述升压模式时所述第三及第四开关的切换周期为一小于所述第二及第三周期的第四周期。12. The power converter according to claim 7, wherein in the step-down mode, the switching period of the first and second switches is a first period; mode, the switching period of the first, second, third and fourth switches is a second period greater than the first period; in the second buck-boost mode, the first, second, The switching period of the third and fourth switches is a third period greater than the first period; in the boost mode, the switching period of the third and fourth switches is a period shorter than the second and third The fourth cycle of the cycle. 13.如权利要求7所述的电源转换器,其特征在于,在所述第一升降压模式时,所述第三及第四开关的责任周期固定。13. The power converter as claimed in claim 7, wherein in the first buck-boost mode, duty periods of the third and fourth switches are fixed. 14.如权利要求7所述的电源转换器,其特征在于,在所述第二升降压模式时,所述第一及第二开关的责任周期固定。14. The power converter as claimed in claim 7, wherein in the second buck-boost mode, duty cycles of the first and second switches are fixed. 15.一种升降压式电源转换器的控制方法,所述电源转换器包含一电感,一第一开关连接在所述电源转换器的输入端及所述电感的第一端之间,一第二开关连接在所述电感的第一端及一接地端之间,一第三开关连接在所述电感的第二端及所述接地端之间,以及一二极管具有一阳极连接所述电感的第二端及一阴极连接所述电源转换器的输出端,其特征在于所述控制方法包括下列步骤:15. A control method for a buck-boost power converter, the power converter includes an inductor, a first switch is connected between the input end of the power converter and the first end of the inductor, and a A second switch is connected between the first terminal of the inductor and a ground terminal, a third switch is connected between the second terminal of the inductor and the ground terminal, and a diode has an anode connected to the inductor The second end and a cathode are connected to the output end of the power converter, characterized in that the control method includes the following steps: 第一步骤:检测所述输入端及输出端上的电压以及所述输出端上的负载电流以决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式;The first step: detecting the voltage on the input terminal and the output terminal and the load current on the output terminal to determine whether the power converter is operating in a buck mode, a first buck-boost mode, or a second buck-boost mode or boost mode; 第二步骤:在所述第一及第二升降压模式时,所述第一、第二及第三开关的控制包含:The second step: in the first and second buck-boost modes, the control of the first, second and third switches includes: (a)关闭所述第一开关,打开所述第二开关,关闭所述第三开关;(a) closing the first switch, opening the second switch, and closing the third switch; (b)打开所述第一开关,关闭所述第二开关,维持所述第三开关关闭;(b) opening the first switch, closing the second switch, and keeping the third switch closed; (c)维持所述第一开关打开,维持所述第二开关关闭,打开所述第三开关。(c) keeping the first switch on, keeping the second switch off, and turning on the third switch. 16.如权利要求15所述的控制方法,其特征在于,所述决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式的步骤包括:16. The control method according to claim 15, wherein the step of determining whether the power converter operates in a buck mode, a first buck-boost mode, a second buck-boost mode or a boost mode comprises : 当所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值小于一第一临界值时,决定所述电源转换器操作在降压模式;When the multiplier value of both ends of the inductor determined by the voltage on the input terminal and the output terminal and the load current on the output terminal is less than a first critical value, it is determined that the power converter operates in a step-down mode. ; 当所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值大于所述第一临界值且小于一第二临界值时,决定所述电源转换器操作在所述第一升降压模式;When the multiplier value at both ends of the inductance determined by the voltage on the input terminal and the output terminal and the load current on the output terminal is greater than the first critical value and less than a second critical value, determine the the power converter operates in the first buck-boost mode; 当所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值小于一第三临界值且大于所述第二临界值时,决定所述电源转换器操作在所述第二升降压模式;当所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值大于所述第三临界值时,决定所述电源转换器操作在所述升压模式。When the multiplier value at both ends of the inductance determined by the voltage on the input terminal and the output terminal and the load current on the output terminal is less than a third critical value and greater than the second critical value, determine the The power converter operates in the second buck-boost mode; when the multiplier value at both ends of the inductor determined by the voltage on the input terminal and the output terminal and the load current on the output terminal is greater than the third threshold value, it is determined that the power converter operates in the boost mode. 17.如权利要求15所述的控制方法,其特征在于,更包括:17. The control method according to claim 15, further comprising: 放大一第一信号及一参考电压之间的差值产生一第二信号,所述第一信号为所述输出端上电压的函数;amplifying a difference between a first signal and a reference voltage to generate a second signal, the first signal being a function of the voltage at the output; 提供一第一频率及一第二频率;providing a first frequency and a second frequency; 根据所述电源转换器的操作模式及所述第一频率产生一第三信号及一第四信号;generating a third signal and a fourth signal according to the operation mode of the power converter and the first frequency; 比较所述第二信号及第三信号产生一第五信号;comparing the second signal and the third signal to generate a fifth signal; 比较所述第二信号及第四信号产生一第六信号;comparing the second signal and the fourth signal to generate a sixth signal; 根据所述电源转换器的操作模式、所述第五及第六信号、第一频率及第二频率控制所述第一、第二及第三开关。The first, second and third switches are controlled according to the operating mode of the power converter, the fifth and sixth signals, the first frequency and the second frequency. 18.如权利要求15所述的控制方法,其特征在于,在所述降压模式时,所述第一及第二开关的切换周期为一第一周期;在所述第一升降压模式时所述第一、第二及第三开关的切换周期为一大于所述第一周期的第二周期;在所述第二升降压模式时所述第一、第二及第三开关的切换周期为一大于所述第一周期的第三周期;在所述升压模式时所述第三开关的切换周期为一小于所述第二及第三周期的第四周期。18. The control method according to claim 15, wherein in the buck mode, the switching period of the first and second switches is a first period; in the first buck-boost mode When the switching period of the first, second and third switches is a second period greater than the first period; in the second buck-boost mode, the switching periods of the first, second and third switches The switching period is a third period longer than the first period; the switching period of the third switch in the boost mode is a fourth period shorter than the second and third periods. 19.如权利要求15所述的控制方法,其特征在于,在所述第一升降压模式时,所述第三开关的责任周期固定。19. The control method according to claim 15, characterized in that, in the first buck-boost mode, the duty cycle of the third switch is fixed. 20.如权利要求15所述的控制方法,其特征在于,在所述第二升降压模式时,所述第一及第二开关的责任周期固定。20. The control method according to claim 15, wherein in the second buck-boost mode, duty periods of the first and second switches are fixed. 21.一种升降压式电源转换器,其特征在于,包括:21. A buck-boost power converter, characterized in that it comprises: 一电感;an inductance; 一第一开关,连接在所述电源转换器的输入端及所述电感的第一端之间;a first switch connected between the input terminal of the power converter and the first terminal of the inductor; 一第二开关,连接在所述电感的第一端及一接地端之间;a second switch connected between the first terminal of the inductor and a ground terminal; 一第三开关,连接在所述电感的第二端及所述接地端之间;a third switch connected between the second terminal of the inductor and the ground terminal; 一二极管,具有一阳极连接所述电感的第二端及一阴极连接所述电源转换器的输出端;a diode having an anode connected to the second end of the inductor and a cathode connected to the output end of the power converter; 一控制电路,控制所述第一、第二、第三及第四开关的切换,并根据所述输入端及输出端上的电压以及所述输出端上的负载电流决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式;a control circuit, controlling switching of the first, second, third and fourth switches, and determining the operation of the power converter according to the voltage on the input terminal and the output terminal and the load current on the output terminal In buck mode, first buck-boost mode, second buck-boost mode or boost mode; 其中,在所述第一及第二升降压模式时,所述第一、第二及第三开关的控制包含(a)关闭所述第一开关、打开所述第二开关及关闭所述第三开关,(b)打开所述第一开关、关闭所述第二开关及维持所述第三开关关闭,以及(c)维持所述第一开关打开、维持所述第二开关关闭及打开所述第三开关。Wherein, in the first and second buck-boost modes, the control of the first, second and third switches includes (a) closing the first switch, opening the second switch and closing the a third switch, (b) opening the first switch, closing the second switch and keeping the third switch closed, and (c) keeping the first switch open, keeping the second switch closed and opening the third switch. 22.如权利要求21所述的电源转换器,其特征在于,控制电路在所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值小于一第一临界值时,决定所述电源转换器操作在所述降压模式;在所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值大于所述第一临界值且小于一第二临界值时,决定所述电源转换器操作在所述第一升降压模式;在所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值小于一第三临界值且大于所述第二临界值时,决定所述电源转换器操作在所述第二升降压模式;在所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值大于所述第三临界值时,决定所述电源转换器操作在所述升压模式。22. The power converter as claimed in claim 21, characterized in that, the control circuit has a multiplier value at both ends of the inductance determined by the voltage on the input terminal and the output terminal and the load current on the output terminal When it is less than a first critical value, it is determined that the power converter operates in the step-down mode; the voltage on the input terminal and the output terminal and the load current on the output terminal determine the inductance When the magnification value of the terminal is greater than the first critical value and smaller than a second critical value, it is determined that the power converter operates in the first buck-boost mode; the voltage on the input terminal and the output terminal is the same as the When the multiplier value at both ends of the inductor determined by the load current on the output terminal is less than a third critical value and greater than the second critical value, it is determined that the power converter operates in the second buck-boost mode; When the multiplier value at both ends of the inductance determined by the voltage on the input terminal and the output terminal and the load current on the output terminal is greater than the third critical value, it is determined that the power converter operates at the boost mode. 23.如权利要求21所述的电源转换器,其特征在于,所述控制电路包括:23. The power converter according to claim 21, wherein the control circuit comprises: 一误差放大器,根据一第一信号及一参考电压产生一第二信号,所述第一信号为所述电源转换器输出端上电压的函数;an error amplifier generating a second signal based on a first signal and a reference voltage, the first signal being a function of the voltage at the output of the power converter; 一频率产生器,提供一第一频率及一第二频率;a frequency generator providing a first frequency and a second frequency; 一模式检测器,检测所述电源转换器的输入端及输出端上的电压产生一第三信号以决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式;A mode detector, detecting the voltage on the input end and the output end of the power converter to generate a third signal to determine whether the power converter is operating in the buck mode, the first buck-boost mode, the second buck-boost mode mode or boost mode; 一锯齿波产生器,根据所述第三信号及第一频率提供一第四信号或一第五信号;a sawtooth wave generator, providing a fourth signal or a fifth signal according to the third signal and the first frequency; 一第一比较器,比较所述第二信号及所述第四信号产生一第六信号;a first comparator, comparing the second signal and the fourth signal to generate a sixth signal; 一第二比较器,比较所述第二信号及所述第五信号产生一第七信号;a second comparator, comparing the second signal and the fifth signal to generate a seventh signal; 一控制逻辑电路,根据所述第三、第六及第七信号以及第一及第二频率控制所述第一、第二及第三开关的切换。A control logic circuit controls switching of the first, second and third switches according to the third, sixth and seventh signals and the first and second frequencies. 24.如权利要求23所述的电源转换器,其特征在于,所述控制逻辑电路包括:24. The power converter according to claim 23, wherein the control logic circuit comprises: 一除频器,对所述第一频率除频产生一第三频率;a frequency divider that divides the first frequency to generate a third frequency; 一第一逻辑电路,根据所述第六信号、第一频率、第二频率、第三频率及一第二参考电压产生一第一控制信号、第二控制信号及第三控制信号及第四控制信号;A first logic circuit, generating a first control signal, a second control signal, a third control signal and a fourth control signal according to the sixth signal, the first frequency, the second frequency, the third frequency and a second reference voltage Signal; 一第一多任务器,根据所述三信号从所述第一、第二、第三及第四控制信号中选取其中之一来控制所述第一及第二开关的切换;A first multiplexer, selecting one of the first, second, third and fourth control signals according to the three signals to control switching of the first and second switches; 一第二逻辑电路,根据所述第七信号、第一频率、第三频率及一第三参考电压产生一第五控制信号、第六控制信号、第七控制信号及第八控制信号;A second logic circuit, generating a fifth control signal, a sixth control signal, a seventh control signal and an eighth control signal according to the seventh signal, the first frequency, the third frequency and a third reference voltage; 一第二多任务器,根据所述第三信号从所述第五、第六、第七及第八控制信号中选取其中之一来控制所述第三开关的切换。A second multiplexer, selecting one of the fifth, sixth, seventh and eighth control signals according to the third signal to control switching of the third switch. 25.如权利要求24所述的电源转换器,其特征在于,所述除频器包括D型正反器。25. The power converter according to claim 24, wherein the frequency divider comprises a D-type flip-flop. 26.如权利要求21所述的电源转换器,其特征在于,在所述降压模式时,所述第一及第二开关的切换周期为一第一周期;在所述第一升降压模式时所述第一、第二及第三开关的切换周期为一大于所述第一周期的第二周期;在所述第二升降压模式时所述第一、第二及第三开关的切换周期为一大于所述第一周期的第三周期;在所述升压模式时所述第三开关的切换周期为一小于所述第二及第三周期的第四周期。26. The power converter according to claim 21, wherein in the step-down mode, the switching period of the first and second switches is a first period; mode, the switching period of the first, second and third switches is a second period greater than the first period; in the second buck-boost mode, the first, second and third switches The switching period of the switch is a third period longer than the first period; the switching period of the third switch in the boost mode is a fourth period shorter than the second and third periods. 27.如权利要求21所述的电源转换器,其特征在于,在所述第一升降压模式时,所述第三开关的责任周期固定。27. The power converter according to claim 21, wherein in the first buck-boost mode, the duty cycle of the third switch is fixed. 28.如权利要求21所述的电源转换器,其特征在于,在所述第二升降压模式时,所述第一及第二开关的责任周期固定。28. The power converter as claimed in claim 21, wherein in the second buck-boost mode, duty periods of the first and second switches are fixed. 29.一种升降压式电源转换器的控制方法,所述电源转换器包含一电感,一第一开关连接在所述电源转换器的输入端及所述电感的第一端之间,一二极管具有一阳极连接一接地端及一阴极连接所述电感的第一端,一第二开关连接在所述电感的第二端及所述接地端之间,以及一第三开关连接在所述电感的第二端及所述电源转换器的输出端之间,其特征在于所述控制方法包括下列步骤:29. A control method for a buck-boost power converter, the power converter includes an inductor, a first switch is connected between the input end of the power converter and the first end of the inductor, and a The diode has an anode connected to a ground terminal and a cathode connected to the first terminal of the inductor, a second switch connected between the second terminal of the inductor and the ground terminal, and a third switch connected to the Between the second end of the inductor and the output end of the power converter, it is characterized in that the control method includes the following steps: 第一步骤:检测所述输入端及输出端上的电压以及所述输出端上的负载电流以决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式;The first step: detecting the voltage on the input terminal and the output terminal and the load current on the output terminal to determine whether the power converter is operating in a buck mode, a first buck-boost mode, or a second buck-boost mode or boost mode; 第二步骤:在所述第一及第二升降压模式时,所述第一、第二及第三开关的控制包含:The second step: in the first and second buck-boost modes, the control of the first, second and third switches includes: (a)关闭所述第一开关,关闭所述第二开关,打开所述第三开关;(a) closing the first switch, closing the second switch, and opening the third switch; (b)打开所述第一开关,维持所述第二开关关闭,维持所述第三开关打开;(b) opening the first switch, keeping the second switch closed, and keeping the third switch open; (c)维持所述第一开关打开,打开所述第二开关,关闭所述第三开关。(c) Keep the first switch open, open the second switch, and close the third switch. 30.如权利要求29所述的控制方法,其特征在于,所述决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式的步骤包括:30. The control method according to claim 29, wherein the step of determining whether the power converter operates in a buck mode, a first buck-boost mode, a second buck-boost mode or a boost mode comprises : 当所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值小于一第一临界值时,决定所述电源转换器操作在降压模式;When the multiplier value of both ends of the inductor determined by the voltage on the input terminal and the output terminal and the load current on the output terminal is less than a first critical value, it is determined that the power converter operates in a step-down mode. ; 当所述输入端及输出端上的与所述输出端上的负载电流所决定出的所述电感两端的倍率值大于所述第一临界值且小于一第二临界值时,决定所述电源转换器操作在所述第一升降压模式;When the multiplier value at both ends of the inductance determined by the load current on the input terminal and the output terminal and the output terminal is greater than the first critical value and less than a second critical value, the power supply is determined the converter operates in said first buck-boost mode; 当所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值小于一第三临界值且大于所述第二临界值时,决定所述电源转换器操作在所述第二升降压模式;When the multiplier value at both ends of the inductance determined by the voltage on the input terminal and the output terminal and the load current on the output terminal is less than a third critical value and greater than the second critical value, determine the the power converter operates in the second buck-boost mode; 当所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值大于所述第三临界值时,决定所述电源转换器操作在所述升压模式。When the multiplier value at both ends of the inductance determined by the voltage on the input terminal and the output terminal and the load current on the output terminal is greater than the third critical value, it is determined that the power converter operates at the boost mode. 31.如权利要求29所述的控制方法,其特征在于,更包括:31. The control method according to claim 29, further comprising: 放大一第一信号及一参考电压之间的差值产生一第二信号,所述第一信号为所述输出端上电压的函数;amplifying a difference between a first signal and a reference voltage to generate a second signal, the first signal being a function of the voltage at the output; 提供一第一频率及一第二频率;providing a first frequency and a second frequency; 根据所述电源转换器的操作模式及所述第一频率产生一第三信号及一第四信号;generating a third signal and a fourth signal according to the operation mode of the power converter and the first frequency; 比较所述第二信号及第三信号产生一第五信号;comparing the second signal and the third signal to generate a fifth signal; 比较所述第二信号及第四信号产生一第六信号;comparing the second signal and the fourth signal to generate a sixth signal; 根据所述电源转换器的操作模式、所述第五及第六信号、第一频率及第二频率控制所述第一、第二及第三开关。The first, second and third switches are controlled according to the operating mode of the power converter, the fifth and sixth signals, the first frequency and the second frequency. 32.如权利要求29所述的控制方法,其特征在于,在所述降压模式时,所述第一开关的切换周期为一第一周期;在所述第一升降压模式时所述第一、第二及第三开关的切换周期为一大于所述第一周期的第二周期;在所述第二升降压模式时所述第一、第二及第三开关的切换周期为一大于所述第一周期的第三周期;在所述升压模式时所述第二及第三开关的切换周期为一小于所述第二及第三周期的第四周期。32. The control method according to claim 29, characterized in that, in the step-down mode, the switching period of the first switch is a first period; in the first buck-boost mode, the The switching period of the first, second and third switches is a second period greater than the first period; in the second buck-boost mode, the switching period of the first, second and third switches is a third period longer than the first period; and a switching period of the second and third switches in the boost mode is a fourth period shorter than the second and third periods. 33.如权利要求29所述的控制方法,其特征在于,在所述第一升降压模式时,所述第二及第三开关的责任周期固定。33. The control method according to claim 29, wherein in the first buck-boost mode, duty periods of the second and third switches are fixed. 34.如权利要求29所述的控制方法,其特征在于,在所述第二升降压模式时,所述第一开关的责任周期固定。34. The control method according to claim 29, wherein in the second buck-boost mode, the duty cycle of the first switch is fixed. 35.一种升降压式电源转换器,其特征在于,包括:35. A buck-boost power converter, characterized in that it comprises: 一电感;an inductance; 一第一开关,连接在所述电源转换器的输入端及所述电感的第一端之间;a first switch connected between the input terminal of the power converter and the first terminal of the inductor; 一二极管,具有一阳极连接一接地端及一阴极连接所述电感的第一端;a diode having an anode connected to a ground terminal and a cathode connected to the first end of the inductor; 一第二开关,连接在所述电感的第二端及所述接地端之间;a second switch connected between the second terminal of the inductor and the ground terminal; 一第三开关,连接在所述电感的第二端及所述电源转换器的输出端之间;a third switch connected between the second end of the inductor and the output end of the power converter; 一控制电路,控制所述第一、第二及第三开关的切换,并根据所述输入端及输出端上的电压以及所述输出端上的负载电流决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式;a control circuit, controlling switching of the first, second and third switches, and determining the step-down operation of the power converter according to the voltage on the input terminal and the output terminal and the load current on the output terminal mode, the first buck-boost mode, the second buck-boost mode or the boost mode; 其中,在所述第一及第二升降压模式时,所述第一、第二及第三开关的控制包含(a)关闭所述第一开关、关闭所述第二开关及打开所述第三开关,(b)打开所述第一开关、维持所述第二开关关闭及维持所述第三开关打开,以及(c)维持所述第一开关打开、打开所述第二开关及关闭所述第三开关。Wherein, in the first and second buck-boost modes, the control of the first, second and third switches includes (a) closing the first switch, closing the second switch and opening the For a third switch, (b) open the first switch, keep the second switch closed and keep the third switch open, and (c) keep the first switch open, open the second switch and close the third switch. 36.如权利要求35所述的电源转换器,其特征在于,所述控制电路在所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值小于一第一临界值时,决定所述电源转换器操作在所述降压模式;在所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值大于一第一临界值且小于一第二临界值时,决定所述电源转换器操作在所述第一升降压模式;在所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值小于一第三临界值且大于所述第二临界值时,决定所述电源转换器操作在所述第二升降压模式;在所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值大于所述第三临界值时,决定所述电源转换器操作在所述升压模式。36. The power converter according to claim 35, characterized in that, the voltage at the input terminal and the output terminal of the control circuit and the load current at the output terminal determine the voltage across the inductance When the magnification value is less than a first critical value, it is determined that the power converter operates in the step-down mode; the voltage on the input terminal and the output terminal and the load current on the output terminal determine the When the multiplier value at both ends of the inductance is greater than a first critical value and smaller than a second critical value, it is determined that the power converter operates in the first buck-boost mode; When the multiplier value at both ends of the inductor determined by the load current at the output terminal is less than a third critical value and greater than the second critical value, it is determined that the power converter operates in the second buck-boost mode ; When the multiplier value at both ends of the inductance determined by the voltage on the input terminal and the output terminal and the load current on the output terminal is greater than the third critical value, it is determined that the power converter operates at the specified boost mode described above. 37.如权利要求35所述的电源转换器,其特征在于,所述控制电路包括:37. The power converter of claim 35, wherein the control circuit comprises: 一误差放大器,根据一第一信号及一参考电压产生一第二信号,所述第一信号为所述电源转换器输出端上电压的函数;an error amplifier generating a second signal based on a first signal and a reference voltage, the first signal being a function of the voltage at the output of the power converter; 一频率产生器,提供一第一频率及一第二频率;a frequency generator providing a first frequency and a second frequency; 一模式检测器,检测所述电源转换器的输入端及输出端上的电压产生一第三信号以决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式;A mode detector, detecting the voltage on the input end and the output end of the power converter to generate a third signal to determine whether the power converter is operating in the buck mode, the first buck-boost mode, the second buck-boost mode mode or boost mode; 一锯齿波产生器,根据所述第三信号及第一频率提供一第四信号或一第五信号;a sawtooth wave generator, providing a fourth signal or a fifth signal according to the third signal and the first frequency; 一第一比较器,比较所述第二信号及所述第四信号产生一第六信号;a first comparator, comparing the second signal and the fourth signal to generate a sixth signal; 一第二比较器,比较所述第二信号及所述第五信号产生一第七信号;a second comparator, comparing the second signal and the fifth signal to generate a seventh signal; 一控制逻辑电路,根据所述第三、第六及第七信号以及第一及第二频率控制所述第一、第二及第三开关的切换。A control logic circuit controls switching of the first, second and third switches according to the third, sixth and seventh signals and the first and second frequencies. 38.如权利要求37所述的电源转换器,其特征在于,所述控制逻辑电路包括:38. The power converter of claim 37, wherein the control logic circuit comprises: 一除频器,对所述第一频率除频产生一第三频率;a frequency divider that divides the first frequency to generate a third frequency; 一第一逻辑电路,根据所述第六信号、第一频率、第二频率、第三频率及一第二参考电压产生一第一控制信号、第二控制信号、第三控制信号及第四控制信号;A first logic circuit, generating a first control signal, a second control signal, a third control signal and a fourth control signal according to the sixth signal, the first frequency, the second frequency, the third frequency and a second reference voltage Signal; 一第一多任务器,根据所述三信号从所述第一、第二、第三及第四控制信号中选取其中之一来控制所述第一开关的切换;A first multiplexer, selecting one of the first, second, third and fourth control signals according to the three signals to control switching of the first switch; 一第二逻辑电路,根据所述第七信号、第一频率、第三频率及一第三参考电压产生一第五控制信号、第六控制信号、第七控制信号及第八控制信号;A second logic circuit, generating a fifth control signal, a sixth control signal, a seventh control signal and an eighth control signal according to the seventh signal, the first frequency, the third frequency and a third reference voltage; 一第二多任务器,根据所述第三信号从所述第五、第六、第七及第八控制信号中选取其中之一来控制所述第二及第三开关的切换。A second multiplexer, selecting one of the fifth, sixth, seventh and eighth control signals according to the third signal to control switching of the second and third switches. 39.如权利要求38所述的电源转换器,其特征在于,所述除频器包括D型正反器。39. The power converter of claim 38, wherein the frequency divider comprises a D-type flip-flop. 40.如权利要求35所述的电源转换器,其特征在于,在所述降压模式时,所述第一开关的切换周期为一第一周期;在所述第一升降压模式时所述第一、第二及第三开关的切换周期为一大于所述第一周期的第二周期;在所述第二升降压模式时所述第一、第二及第三开关的切换周期为一大于所述第一周期的第三周期;在所述升压模式时所述第二及第三开关的切换周期为一小于所述第二及第三周期的第四周期。40. The power converter according to claim 35, wherein in the buck mode, the switching period of the first switch is a first period; in the first buck-boost mode, the The switching period of the first, second and third switches is a second period greater than the first period; the switching period of the first, second and third switches in the second buck-boost mode is a third period longer than the first period; in the boost mode, the switching period of the second and third switches is a fourth period shorter than the second and third periods. 41.如权利要求35所述的电源转换器,其特征在于,在所述第一升降压模式时,所述第二及第三开关的责任周期固定。41. The power converter as claimed in claim 35, wherein in the first buck-boost mode, duty cycles of the second and third switches are fixed. 42.如权利要求35所述的电源转换器,其特征在于,在所述第二升降压模式时,所述第一开关的责任周期固定。42. The power converter according to claim 35, wherein in the second buck-boost mode, the duty cycle of the first switch is fixed. 43.一种升降压式电源转换器的控制方法,所述电源转换器包含一电感,一第一开关连接在所述电源转换器的输入端及所述电感的第一端之间,一第一二极管具有一阳极连接一接地端及一阴极连接所述电感的第一端,一第二开关连接在所述电感的第二端及所述接地端之间,以及一第二二极管具有一阳极连接所述电感的第二端及一阴极连接所述电源转换器的输出端,其特征在于所述控制方法包括下列步骤:43. A control method for a buck-boost power converter, the power converter includes an inductor, a first switch is connected between the input end of the power converter and the first end of the inductor, and a The first diode has an anode connected to a ground terminal and a cathode connected to the first terminal of the inductor, a second switch connected between the second terminal of the inductor and the ground terminal, and a second The pole tube has an anode connected to the second end of the inductor and a cathode connected to the output end of the power converter, wherein the control method includes the following steps: 第一步骤:检测所述输入端及输出端上的电压以及所述输出端上的负载电流以决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式;The first step: detecting the voltage on the input terminal and the output terminal and the load current on the output terminal to determine whether the power converter is operating in a buck mode, a first buck-boost mode, or a second buck-boost mode or boost mode; 第二步骤:在所述第一及第二升降压模式时,所述第一及第二开关的控制包含:The second step: in the first and second buck-boost modes, the control of the first and second switches includes: (a)关闭所述第一开关,关闭所述第二开关;(a) closing the first switch and closing the second switch; (b)打开所述第一开关,维持所述第二开关关闭;(b) opening the first switch and keeping the second switch closed; (c)维持所述第一开关打开,打开所述第二开关。(c) Keeping the first switch open and turning on the second switch. 44.如权利要求43所述的控制方法,其特征在于,所述决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式的步骤包括:44. The control method according to claim 43, wherein the step of determining whether the power converter operates in a buck mode, a first buck-boost mode, a second buck-boost mode or a boost mode comprises : 当所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值小于一第一临界值时,决定所述电源转换器操作在降压模式;When the multiplier value of both ends of the inductor determined by the voltage on the input terminal and the output terminal and the load current on the output terminal is less than a first critical value, it is determined that the power converter operates in a step-down mode. ; 当所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值大于所述第一临界值且小于一第二临界值时,决定所述电源转换器操作在所述第一升降压模式;When the multiplier value at both ends of the inductance determined by the voltage on the input terminal and the output terminal and the load current on the output terminal is greater than the first critical value and less than a second critical value, determine the the power converter operates in the first buck-boost mode; 当所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值小于一第三临界值且大于所述第二临界值时,决定所述电源转换器操作在所述第二升降压模式;When the multiplier value at both ends of the inductance determined by the voltage on the input terminal and the output terminal and the load current on the output terminal is less than a third critical value and greater than the second critical value, determine the the power converter operates in the second buck-boost mode; 当所述输入端及输出端上的电压与负载电流所决定出的所述电感两端的倍率值大于所述第三临界值时,决定所述电源转换器操作在所述升压模式。When the multiplier value at both ends of the inductor determined by the voltage on the input terminal and the output terminal and the load current is greater than the third critical value, it is determined that the power converter operates in the boost mode. 45.如权利要求43所述的控制方法,其特征在于,更包括:45. The control method according to claim 43, further comprising: 放大一第一信号及一参考电压之间的差值产生一第二信号,所述第一信号为所述输出端上电压的函数;amplifying a difference between a first signal and a reference voltage to generate a second signal, the first signal being a function of the voltage at the output; 提供一第一频率及一第二频率;providing a first frequency and a second frequency; 根据所述电源转换器的操作模式及所述第一频率产生一第三信号及一第四信号;generating a third signal and a fourth signal according to the operation mode of the power converter and the first frequency; 比较所述第二信号及第三信号产生一第五信号;comparing the second signal and the third signal to generate a fifth signal; 比较所述第二信号及第四信号产生一第六信号;comparing the second signal and the fourth signal to generate a sixth signal; 根据所述电源转换器的操作模式、所述第五及第六信号、第一频率及第二频率控制所述第一及第二开关。The first and second switches are controlled according to the operating mode of the power converter, the fifth and sixth signals, the first frequency and the second frequency. 46.如权利要求43所述的控制方法,其特征在于,在所述降压模式时,所述第一开关的切换周期为一第一周期;在所述第一升降压模式时所述第一及第二开关的切换周期为一大于所述第一周期的第二周期;在所述第二升降压模式时所述第一及第二开关的切换周期为一大于所述第一周期的第三周期;在所述升压模式时所述第二开关的切换周期为一小于所述第二及第三周期的第四周期。46. The control method according to claim 43, characterized in that, in the step-down mode, the switching period of the first switch is a first period; in the first buck-boost mode, the The switching period of the first and second switches is a second period greater than the first period; in the second buck-boost mode, the switching period of the first and second switches is a period greater than the first period A third period of the period; in the boost mode, the switching period of the second switch is a fourth period shorter than the second and third periods. 47.如权利要求43所述的控制方法,其特征在于,在所述第一升降压模式时,所述第二开关的责任周期固定。47. The control method according to claim 43, wherein in the first buck-boost mode, the duty cycle of the second switch is fixed. 48.如权利要求43所述的控制方法,其特征在于,在所述第二升降压模式时,所述第一开关的责任周期固定。48. The control method according to claim 43, wherein in the second buck-boost mode, the duty cycle of the first switch is fixed. 49.一种升降压式电源转换器,其特征在于,包括:49. A buck-boost power converter, characterized by comprising: 一电感;an inductance; 一第一开关,连接在所述电源转换器的输入端及所述电感的第一端之间;a first switch connected between the input terminal of the power converter and the first terminal of the inductor; 一第一二极管,具有一阳极连接一接地端及一阴极连接所述电感的第一端;a first diode having an anode connected to a ground terminal and a cathode connected to the first end of the inductor; 一第二开关,连接在所述电感的第二端及所述接地端之间;a second switch connected between the second terminal of the inductor and the ground terminal; 一第二二极管,具有一阳极连接所述电感的第二端及一阴极连接所述电源转换器的输出端;A second diode, having an anode connected to the second end of the inductor and a cathode connected to the output end of the power converter; 一控制电路,控制所述第一及第二开关的切换,并根据所述输入端及输出端上的电压以及所述输出端上的负载电流决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式;A control circuit, controlling switching of the first and second switches, and determining the power converter to operate in step-down mode, the second A buck-boost mode, a second buck-boost mode or a boost mode; 其中,在所述第一及第二升降压模式时,所述第一及第二开关的控制包含(a)关闭所述第一开关及关闭所述第二开关,(b)打开所述第一开关及维持所述第二开关关闭,以及(c)维持所述第一开关打开及打开所述第二开关。Wherein, in the first and second buck-boost modes, the control of the first and second switches includes (a) closing the first switch and closing the second switch, (b) opening the first switch and maintaining said second switch closed, and (c) maintaining said first switch open and opening said second switch. 50.如权利要求49所述的电源转换器,其特征在于,所述控制电路在当所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值小于一第一临界值时,决定所述电源转换器操作在所述降压模式;在所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值大于所述第一临界值且小于一第二临界值时,决定所述电源转换器操作在所述第一升降压模式;在所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值小于一第三临界值且大于所述第二临界值时,决定所述电源转换器操作在所述第二升降压模式;在所述输入端及输出端上的电压与所述输出端上的负载电流所决定出的所述电感两端的倍率值大于所述第三临界值时,决定所述电源转换器操作在所述升压模式。50. The power converter according to claim 49, wherein the control circuit operates between the inductance determined by the voltage on the input terminal and the output terminal and the load current on the output terminal. When the multiplier value of the terminal is less than a first critical value, it is determined that the power converter operates in the step-down mode; the voltage on the input terminal and the output terminal and the load current on the output terminal are determined by the When the multiplier value at both ends of the inductance is greater than the first critical value and smaller than a second critical value, it is determined that the power converter operates in the first buck-boost mode; the voltage on the input terminal and the output terminal When the multiplier value at both ends of the inductance determined by the load current on the output terminal is less than a third critical value and greater than the second critical value, it is determined that the power converter operates at the second lifting voltage mode; when the multiplier value at both ends of the inductance determined by the voltage on the input terminal and the output terminal and the load current on the output terminal is greater than the third critical value, the operation of the power converter is determined in the boost mode. 51.如权利要求49所述的电源转换器,其特征在于,所述控制电路包括:51. The power converter of claim 49, wherein the control circuit comprises: 一误差放大器,根据一第一信号及一参考电压产生一第二信号,所述第一信号为所述电源转换器输出端上电压的函数;an error amplifier generating a second signal based on a first signal and a reference voltage, the first signal being a function of the voltage at the output of the power converter; 一频率产生器,提供一第一频率及一第二频率;a frequency generator providing a first frequency and a second frequency; 一模式检测器,检测所述电源转换器的输入端及输出端上的电压产生一第三信号以决定所述电源转换器操作在降压模式、第一升降压模式、第二升降压模式或升压模式;A mode detector, detecting the voltage on the input end and the output end of the power converter to generate a third signal to determine whether the power converter is operating in the buck mode, the first buck-boost mode, the second buck-boost mode mode or boost mode; 一锯齿波产生器,根据所述第三信号及第一频率提供一第四信号或一第五信号;a sawtooth wave generator, providing a fourth signal or a fifth signal according to the third signal and the first frequency; 一第一比较器,比较所述第二信号及所述第四信号产生一第六信号;a first comparator, comparing the second signal and the fourth signal to generate a sixth signal; 一第二比较器,比较所述第二信号及所述第五信号产生一第七信号;a second comparator, comparing the second signal and the fifth signal to generate a seventh signal; 一控制逻辑电路,根据所述第三、第六及第七信号以及第一及第二频率控制所述第一及第二开关的切换。A control logic circuit controls switching of the first and second switches according to the third, sixth and seventh signals and the first and second frequencies. 52.如权利要求51所述的电源转换器,其特征在于,所述控制逻辑电路包括:52. The power converter of claim 51, wherein the control logic circuit comprises: 一除频器,对所述第一频率除频产生一第三频率;a frequency divider that divides the first frequency to generate a third frequency; 一第一逻辑电路,根据所述第六信号、第一频率、第二频率、第三频率及一第二参考电压产生一第一控制信号、第二控制信号、第三控制信号及第四控制信号;A first logic circuit, generating a first control signal, a second control signal, a third control signal and a fourth control signal according to the sixth signal, the first frequency, the second frequency, the third frequency and a second reference voltage Signal; 一第一多任务器,根据所述三信号从所述第一、第二、第三及第四控制信号中选取其中之一来控制所述第一开关的切换;A first multiplexer, selecting one of the first, second, third and fourth control signals according to the three signals to control switching of the first switch; 一第二逻辑电路,根据所述第七信号、第一频率、第三频率及一第三参考电压产生一第五控制信号、第六控制信号、第七控制信号及第八控制信号;A second logic circuit, generating a fifth control signal, a sixth control signal, a seventh control signal and an eighth control signal according to the seventh signal, the first frequency, the third frequency and a third reference voltage; 一第二多任务器,根据所述第三信号从所述第五、第六、第七及第八控制信号中选取其中之一来控制所述第二开关的切换。A second multiplexer, selecting one of the fifth, sixth, seventh and eighth control signals according to the third signal to control switching of the second switch. 53.如权利要求52所述的电源转换器,其特征在于,所述除频器包括D型正反器。53. The power converter of claim 52, wherein the frequency divider comprises a D-type flip-flop. 54.如权利要求49所述的电源转换器,其特征在于,在所述降压模式时,所述第一开关的切换周期为一第一周期;在所述第一升降压模式时所述第一及第二开关的切换周期为一大于所述第一周期的第二周期;在所述第二升降压模式时所述第一及第二开关的切换周期为一大于所述第一周期的第三周期;在所述升压模式时所述第二开关的切换周期为一小于所述第二及第三周期的第四周期。54. The power converter according to claim 49, wherein in the buck mode, the switching cycle of the first switch is a first cycle; in the first buck-boost mode, the The switching period of the first and second switches is a second period greater than the first period; in the second buck-boost mode, the switching period of the first and second switches is a period greater than the first period A third period of one period; in the boost mode, the switching period of the second switch is a fourth period shorter than the second and third periods. 55.如权利要求49所述的电源转换器,其特征在于,在所述第一升降压模式时,所述第二开关的责任周期固定。55. The power converter according to claim 49, wherein in the first buck-boost mode, the duty cycle of the second switch is fixed. 56.如权利要求49所述的电源转换器,其特征在于,在所述第二升降压模式时,所述第一开关的责任周期固定。56. The power converter of claim 49, wherein in the second buck-boost mode, the duty cycle of the first switch is fixed.
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Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103595275A (en) * 2012-08-16 2014-02-19 台达电子工业股份有限公司 Hybrid DC to AC conversion system and method of operation thereof
CN103633627A (en) * 2013-11-07 2014-03-12 矽力杰半导体技术(杭州)有限公司 Method and circuit for overvoltage protection control of four-switch Buck-Boost converter
CN103715886A (en) * 2013-12-11 2014-04-09 矽力杰半导体技术(杭州)有限公司 Four-switch buck/boost mode converter control method and control circuit
CN103872933A (en) * 2012-12-18 2014-06-18 立锜科技股份有限公司 Power converter, related control circuit and method
CN103874271A (en) * 2012-12-18 2014-06-18 立锜科技股份有限公司 Power converter, related control circuit and method
CN104158399A (en) * 2014-08-27 2014-11-19 圣邦微电子(北京)股份有限公司 Single-inductor positive and negative voltage output device
CN104660039A (en) * 2013-11-21 2015-05-27 青岛润鑫伟业科贸有限公司 Liftable efficient switch power supply circuit
CN105099192A (en) * 2015-09-30 2015-11-25 深圳天珑无线科技有限公司 Output voltage regulating circuit of power supply and control method of output voltage regulating circuit of power supply
CN107276410A (en) * 2016-04-05 2017-10-20 株式会社万都 The power control unit and method of vehicle
CN110138212A (en) * 2019-06-01 2019-08-16 深圳市永航新能源技术有限公司 Half-bridge driven no dead-time control method, control device and charging equipment
CN111262434A (en) * 2020-02-20 2020-06-09 上海南芯半导体科技有限公司 Buck-boost DC-DC converter and control method
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US11552555B2 (en) * 2020-12-31 2023-01-10 Texas Instruments Incorporated Circuit electromagnetic interference control
US20230208295A1 (en) * 2021-12-28 2023-06-29 Novatek Microelectronics Corp. Power supply circuit for switching converter

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI551021B (en) * 2015-11-25 2016-09-21 財團法人金屬工業研究發展中心 Flyback power converter and control method thereof

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6166527A (en) * 2000-03-27 2000-12-26 Linear Technology Corporation Control circuit and method for maintaining high efficiency in a buck-boost switching regulator
US20050206354A1 (en) * 2003-12-25 2005-09-22 Katsuya Ikezawa DC-DC converter
TW200625050A (en) * 2004-09-14 2006-07-16 Linear Techn Inc Adaptive control for inductor based buck-boost voltage regulators
US20060284606A1 (en) * 2005-06-20 2006-12-21 Tien-Tzu Chen Buck-boost voltage converter
US20080001587A1 (en) * 2006-06-30 2008-01-03 Analog Devices, Inc. DC to DC voltage converter
US20090108823A1 (en) * 2007-10-31 2009-04-30 Elite Micropower Inc. Control circuit and method for maintaining high efficiency in switching regulator

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6166527A (en) * 2000-03-27 2000-12-26 Linear Technology Corporation Control circuit and method for maintaining high efficiency in a buck-boost switching regulator
US20050206354A1 (en) * 2003-12-25 2005-09-22 Katsuya Ikezawa DC-DC converter
TW200625050A (en) * 2004-09-14 2006-07-16 Linear Techn Inc Adaptive control for inductor based buck-boost voltage regulators
US20060284606A1 (en) * 2005-06-20 2006-12-21 Tien-Tzu Chen Buck-boost voltage converter
US20080001587A1 (en) * 2006-06-30 2008-01-03 Analog Devices, Inc. DC to DC voltage converter
US20090108823A1 (en) * 2007-10-31 2009-04-30 Elite Micropower Inc. Control circuit and method for maintaining high efficiency in switching regulator

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103595275B (en) * 2012-08-16 2017-03-01 台达电子工业股份有限公司 Hybrid DC to AC conversion system and method of operation thereof
CN103595275A (en) * 2012-08-16 2014-02-19 台达电子工业股份有限公司 Hybrid DC to AC conversion system and method of operation thereof
CN103872933A (en) * 2012-12-18 2014-06-18 立锜科技股份有限公司 Power converter, related control circuit and method
CN103874271A (en) * 2012-12-18 2014-06-18 立锜科技股份有限公司 Power converter, related control circuit and method
CN103874271B (en) * 2012-12-18 2015-08-19 立锜科技股份有限公司 Power converter, related control circuit and method
CN103872933B (en) * 2012-12-18 2015-09-02 立锜科技股份有限公司 Power converter, related control circuit and method
US9543822B2 (en) 2013-11-07 2017-01-10 Silergy Semiconductor Technology (Hangzhou) Ltd Over voltage protection control method and circuit for four-switch buck-boost converter
CN103633627A (en) * 2013-11-07 2014-03-12 矽力杰半导体技术(杭州)有限公司 Method and circuit for overvoltage protection control of four-switch Buck-Boost converter
US10003263B2 (en) 2013-11-07 2018-06-19 Silergy Semiconductor Technology (Hangzhou) Ltd Over voltage protection control method and circuit for four-switch buck-boost converter
CN104660039A (en) * 2013-11-21 2015-05-27 青岛润鑫伟业科贸有限公司 Liftable efficient switch power supply circuit
CN103715886A (en) * 2013-12-11 2014-04-09 矽力杰半导体技术(杭州)有限公司 Four-switch buck/boost mode converter control method and control circuit
CN103715886B (en) * 2013-12-11 2017-01-11 矽力杰半导体技术(杭州)有限公司 Four-switch buck/boost mode converter control method and control circuit
US9698690B2 (en) 2013-12-11 2017-07-04 Silergy Semiconductor Technology (Hangzhou) Ltd Control method and control circuit for four-switch buck-boost converter
CN104158399A (en) * 2014-08-27 2014-11-19 圣邦微电子(北京)股份有限公司 Single-inductor positive and negative voltage output device
CN105099192A (en) * 2015-09-30 2015-11-25 深圳天珑无线科技有限公司 Output voltage regulating circuit of power supply and control method of output voltage regulating circuit of power supply
CN105099192B (en) * 2015-09-30 2018-05-08 深圳天珑无线科技有限公司 The output voltage regulation circuit and its control method of power supply
CN107276410B (en) * 2016-04-05 2020-07-31 株式会社万都 Power control device and method for vehicle
CN107276410A (en) * 2016-04-05 2017-10-20 株式会社万都 The power control unit and method of vehicle
US10377249B2 (en) 2016-04-05 2019-08-13 Mando Corporation Vehicle power control device and method
CN110138212A (en) * 2019-06-01 2019-08-16 深圳市永航新能源技术有限公司 Half-bridge driven no dead-time control method, control device and charging equipment
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