CN203813658U - Switching voltage regulator - Google Patents
Switching voltage regulator Download PDFInfo
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- CN203813658U CN203813658U CN201320763879.6U CN201320763879U CN203813658U CN 203813658 U CN203813658 U CN 203813658U CN 201320763879 U CN201320763879 U CN 201320763879U CN 203813658 U CN203813658 U CN 203813658U
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Abstract
The utility model discloses a switching voltage regulator, and provides a circuit and a method for controlling the switching voltage regulator. The method comprises: 1, a switch comprises one or more switching transistors; 2, a current output for adjusting a voltage is suitable for a load, wherein the load comprises an output capacitor. When the voltage of an output end can maintain that the output capacitor discharges to an adjusting voltage basically, the circuit and the method generate a control signal for switching off one or more switching transistors under the condition of working. The circuit and the method improve the efficiency of a voltage regulator circuit, especially under a low average current.
Description
Technical field:
The present invention relates to a switching regulator circuit.More particularly, the present invention relates under very wide current range, keep in a kind of switching regulator high efficiency control circuit and method.
Background technology:
The object of Voltagre regulator is to utilize an input voltage source unsettled and fluctuation to provide a default and constant output voltage for a load.In general, there is the pressurizer of two types: series voltage regulator and switching regulator.
Series voltage regulator adopts a bypass elements (for example, a power transistor) to be coupled in series in a load, to control the voltage drop on bypass elements, for the voltage in regulating load.On the contrary, switching regulator adopts switch (for example a, a power transistor) series coupled or is coupled in parallel in load.The opening and closing of pressurizer control switch, for the power in regulating load.Switching regulator adopts inductive energy storage element, and switched current pulse is become to stable load current.Therefore, the power of switching regulator transmits switch discrete current pulses, and in series voltage regulator, power transmits stable electric current by element.
For generation current pulse, switching regulator generally includes control circuit, the Kai Heguan of control switch.Duty cycle of switching, can use a lot of diverse ways, controls the power that flows to load.For example, duty ratio, can change time of fixedly opening and closing in time (2) each pulse of opening and closing in the frequency of (1) fixed pulse stream and each pulse and the frequency of different stream of pulsess.
For other the method for control duty ratio, switching regulator is conventionally more effective than series voltage regulator.In series voltage regulator, bypass elements is usually operated in its range of linearity, and bypass elements continues generation current.This causes continuous loss power on pass-transistor.On the contrary, in switching regulator, when switch cuts out, there is no power loss on switch, switch opens, under low-impedance state, only has a small amount of power loss on switch.Difference in this work, reduces the average loss power of switching regulator.
In the time that the input-output voltage differences of pressurizer is very large, above-mentioned efficiency is more obvious.For example, the efficiency of series voltage regulator is very abnormal lower than 25%, and switching regulator is in the time reaching said function, and efficiency is greater than 75%.
Due to the raising of series voltage regulator efficiency, switching regulator adopts battery power supply system conventionally, as portable notebook computer computer and handheld instrument.In these systems, in the time that switching regulator provides one to approach output-current rating (that is, in portable notebook computer computer, disk or hard drive are opened), the efficiency of whole circuit can be enhanced.But efficiency is a function of output current normally, reduces along with reducing of output current.The reduction of this efficiency is by switching regulator work time, and associated loss causes.Except above-mentioned loss, these losses comprise, the loss of quiescent current in regulator control circuit, switching losses, switched drive current loss and inductance, transformer winding and core losses.
In the time of low output current, the reduction of switching regulator efficiency, in battery power supply system, it is very important that this problem becomes, so it is desirable making maximise battery life.
In sum, design need to provide a high efficiency switch pressurizer.
It also needs to provide a kind of switching regulator circuit under very wide current range, to keep high efficiency control circuit and method, also comprises low output current.
Summary of the invention:
First object of the present invention is to provide a high efficiency switch pressurizer.
Second object of the present invention is to provide a kind of switching regulator circuit and under very wide current range, keeps high efficiency control circuit and method, also comprises low output current.
Technical solution of the present invention:
According to these and other some objects of the present invention, circuit and the method for the control switch Voltagre regulator providing, comprise that (1) switch comprises that the electric current output of (2) regulation voltages of one or more switching transistors is applicable to a load, this load comprises an output capacitance.Be discharged to regulation voltage (, in the time of low output current) when the voltage of output can keep output capacitance substantially, the in the situation that of work, sort circuit and method, produce control signal and close one or more switching transistor.During this period of time, not loss of load input power power.Therefore, the efficiency of pressurizer rises.If necessary, other compositions of switching regulator, except switching transistor, state that can be in closing, to preserve more electricity.This extra feature of the present invention, can increase the efficiency of whole voltage regulator circuit.
Sort circuit of the present invention and method can control switch voltage regulator circuit various switches, comprise the switch that uses one or more power transistors.In addition, sort circuit and method can control switch voltage stabilizing the various switches of configuration, comprise and boosting, step-down and pole reversal configuration.
In addition, sort circuit of the present invention and method can change the shut-in time of switching transistor, and it depends on the input and output voltage of switching regulator.Under low-voltage condition, this function of the present invention has reduced dispersing of audible noise in switching regulator.When some pressurizers are configured in short circuit, it can also reduce the leakage current on output voltage.
Contrast patent documentation: CN201149666Y regulator control circuit 200820055379.6, the control circuit structure 201320129254.4 of a CN203204478U pressurizer
Brief description of the drawings:
Above-mentioned object and the advantage with other of the present invention will be done detailed description below, takes corresponding brief description of the drawings, and the reference symbol of each element is all indicated in the drawings.
Shown in Fig. 1 is the theory diagram of the switching regulator circuit of prior art, and it has adopted the switch of a pair of synchro switch MOSFET under pressure-lowering condition.
Shown in Fig. 2 is the theory diagram of switching regulator circuit, and its first example with efficient control circuit of the present invention removes to drive a switch, and this switch, under pressure-lowering condition, has adopted the switch of a pair of synchro switch MOSFET.
Shown in Fig. 3 is the theory diagram of switching regulator circuit, and its second example with efficient control circuit of the present invention removes to drive a switch, and this switch, under pressure-lowering condition, has adopted the switch of a pair of synchro switch MOSFET.
Shown in Fig. 4 is the theory diagram of switching regulator circuit, and it in conjunction with " user's activation " mode, removes to drive a switch with efficient control circuit of the present invention, and this switch, under pressure-lowering condition, has adopted the switch of a pair of synchro switch MOSFET.
Shown in Fig. 5 is the theory diagram of switching regulator circuit, and it combines variable shut-in time control circuit of the present invention.
Shown in Fig. 6 is the detailed schematic diagram of variable shut-in time control circuit in Fig. 5.
Shown in Fig. 7 is the detailed theory diagram of an exemplary switching regulator circuit, it combines feature and the efficient control circuit of the present invention of shut-in time, to drive a switch, this switch, under pressure-lowering condition, has adopted the switch of a pair of synchro switch MOSFET.
Shown in Fig. 8 is the detailed theory diagram of a switching regulator circuit, and it combines circuit of the present invention, and reverse to prevent the electric current on pressurizer outputting inductance, this electric current comes from load.
Shown in Fig. 9 is the detailed theory diagram of a switching regulator circuit, and under the condition of boosting, it combines efficient control circuit of the present invention.
Shown in Figure 10 is the detailed theory diagram of a switching regulator circuit, and under the condition of the pole reversal, it combines efficient control circuit of the present invention.
Embodiment:
Shown in Fig. 1 is the theory diagram of the switching regulator circuit of prior art, and it has adopted a push-pull switch under pressure-lowering condition.
With reference to figure 1, circuit 10 be pressurizer at terminal 12(, 5 volts) on a VD V is provided
oUT, to drive load 14, for example, may be portable notebook computer computer or other battery power supply system.When circuit 10 is worked, astable voltage source V
iNbe coupling in terminal 14(, 12 volts of batteries) on.Circuit 10 comprises push-pull switch 15, drive circuit 20, output circuit 30 and control circuit 35.
Drive circuit 20 is for driving push-pull switch 15, and it comprises two synchro switch power MOSFETS 16(P raceway grooves) and 17(N raceway groove), be connected in series in V
iNand between earth point.
Push-pull switch 15 is connected with drive circuit 20, is commonly called " half-bridge " device.MOSFETS16 and 17 is used to as output circuit 30 provides electric current alternately, and it comprises inductance 32(L
1) and output capacitance 34(C
oUT).Output circuit 30 is exchanging electric current electric current smoothly, makes load 12 regulation voltage V
oUT.For alternative current is provided, MOSFETS16 and 17 is driven by the driving 26 of P raceway groove and N raceway groove driving 27 respectively, and this is all controlled by control circuit 35 conversely.
Control circuit 35 comprises single-shot trigger circuit, 26 MOSFET16 is closed driving, and during driving 27 MOSFET17 is opened, it provides the pulse of closing of a constant duration (as, 2 to 10 microseconds).Otherwise, to open at MOSFET16, the MOSFET17 down periods, single-shot trigger circuit 25 provides one to open pulse.Therefore, the opening and closing that single-shot trigger circuit 25 replaces MOSFET16 and MOSFET17, thus provide an electric current replacing for output circuit 30.The duty ratio of single-shot trigger circuit 35 is controlled by current amplifier 39.
Control circuit 35 monitoring resistor-driving network R
1/ R
2(36A/36B) output voltage V on
oUT, so that one and output voltage V to be provided
oUTproportional feedback voltage V
fB.Control circuit 35 is monitored inductance L simultaneously
1on electric current I
l, so that one and inductive current I to be provided
lproportional feedback current I
fB.The work of circuit 10 is by inductive current I
lcontrol, so feedback voltage V
fBvalue be prescribed, be substantially equal to the reference voltage V that reference circuit 37 provides
rEF.Due to feedback voltage V
fBbe prescribed, conversely, output voltage V
oUTby (R
1+ R
2) and R
2a high voltage defined of ratio.
Trsanscondutance amplifier 38 is used for comparison feedback voltage V
fBwith reference voltage V
rEFvalue.Circuit 10 specifies output voltage V
oUT, as follows.Within each cycle, open when switch 15, P-MOSFET16 opens, inductance L
1on electric current I
lbe on ramp and rise, it depends on V
iN-V
oUTthe output 38A of trsanscondutance amplifier 38 makes I
lwhen being ramp and rising to threshold value, current comparator 39 saltus steps, single triggering closed pulse-triggered, and the cycle of closing of switch 15 starts.During the cycle of closing, single-shot trigger circuit 25 is closed P-MOSFET16, and N-MOSFET17 opens.This makes again inductance L conversely
1on electric current I
lbe ramp and decline, it depends on V
oUT.Therefore, this makes duty ratio that switch 15 cuts out the cycle by electric current I
lthe output voltage V producing on terminal 12
oUTinstitute controls.
Along with the increase of output load current, R
2voltage drop on resistance 36B will increase.This makes the increase of error voltage very little on the input 38B of trsanscondutance amplifier 38, and therefore, current comparator 39 has been set a very high threshold value.Therefore, inductance L
1on electric current I
lbe increased to this level, providing of load current is provided.
As the shut-in time of single-shot trigger circuit 25 (t
off) be constant, the inductance L of switching regulator circuit 10
1(constant output voltage V
oUT) on have a constant ripple current, still, V
iNfrequency be different.Ripple concussion frequency is by formula:
A shortcoming of circuit 10 shown in Fig. 1 is, ripple frequency of oscillation f
rIPat low input V
iNcondition under, may drop to the level that can listen.If this thing happens, that is, battery powered switching regulator circuit is equivalent in electric discharge.Inductance L
1may produce noise, this is to adopt voltage regulator circuit institute unacceptable.
Another shortcoming of circuit 10 is, works as output voltage V
oUTwhen short circuit grounding, inductive current I
lcan not well be controlled.The relation of inductive current and voltage is as the formula di/dt=V/L providing.This means inductance L
1on electric current I
ldecay within the shut-in time depends on inductance L
1on voltage, i.e. V
oUTrain supply V with N-MOSFET17
dSsummation.During short circuit, work as V
dSvery little time, V
oUTvoltage close to zero, at t
offduring this time, make inductance L
1on electric current I
lthere is a very little decay.But within each shutdown cycle, P-MOSFET16 opens again, until current comparator 39 produces the constant shut-in time of single triggering again with control circuit 25.Even if the time that P-MOSFET16 opens is very short, inductance L
1on electric current I
lthe amount that the amount increasing declines within the shut-in time than it is large.In this case, short circuit current may reach the level of a destruction.
Another shortcoming of the circuit 10 of prior art comes from inductance L
1constant ripple.In the down periods, inductance L
1on electric current I
lbe slope and decline, its size is identical with the output current of pressurizer.Very low output current may cause inductance L
1on electric current reverse, thereby, draw power from load.During opening, electric current is again on slope and rises, and makes average inductor current equal the electric current that load is lost, it is relevant to constant ripple current, due to the charging and discharging of the MOSFET door of switch 15, along with the loss of switch, can, in the case of low output current, produce very large efficiency.More particularly, inductance L
1on electric current reverse, load is by N-MOSFET17, to earth point transferring electric power.
Another shortcoming of the circuit 10 of prior art is, door driving P-MOSFET16 and N-MOSFET17.Drive 26 and 27 to have a delay, before guaranteeing that a power MOSFET is opened therein, another is closed.If deficiency interval time of two MOSFET (because Equipment, processing of circuit, or the variation of temperature), electric current will be from input terminal V
iNdirectly flow to earth point.This " leading directly to " may lower efficiency significantly, identical in the situation that, may cause overheated and damage power MOSFET.
Shown in Fig. 2 is the theory diagram of switching regulator circuit, and its first example with efficient control circuit of the present invention removes to drive a switch, and this switch, under pressure-lowering condition, has adopted the switch of a pair of synchro switch MOSFET.
Switching regulator circuit 50 comprises push-and-pull switch 15, drive circuit 20 and output circuit 30, and these elements are similar to Fig. 1.Circuit 50 also comprises that one of efficient control circuit of the present invention is embodied 70.
Control circuit 70 comprises single-shot trigger circuit 25, current comparator 39 and amplifier 38, and these elements are similar to Fig. 1.But except these elements, control circuit 70 also comprises constant-current source I
172 and hysteresis comparator 74, with under low average current level, provide very high efficiency.
To discuss in more detail below, constant-current source I
172 and comparator 74 also can push-and-pull switch 15, with the state of the work of entering, as output capacitance C
oUTregulation voltage V
rEGlarge physical efficiency keeps output voltage V
oUTtime, MOSFET16 and 17 closes simultaneously.This operating state is called as " sleep pattern ".Push-pull switch 15 enters in the voltage regulator circuit of this sleep pattern and Fig. 1, free in, a pattern contrast of always opening in MOSFET16 and 17.This feature of the present invention, has reduced the power loss of voltage regulator circuit, because push-pull switch 15 does not have loss power, under sleep pattern, allows power from load R
ltransfer to earth point.
In addition,, if when push-pull switch 15 is in above-mentioned sleep pattern, voltage regulator circuit can be closed other circuit elements, and does not need pressurizer in sleep pattern.For example, in the embodiment of the present invention shown in Fig. 2, single-shot trigger circuit 25, current comparator 39, current source I
172 and amplifier 38, under sleep pattern, can be closed.This feature of the present invention, the efficiency that makes voltage regulator circuit is more taller than the efficiency of only having push-pull switch 15 when the sleep pattern.
Under high load current level (that is, and be greater than maximum rated output current 20 percent), control the operating state of electric current 70 similar to the control circuit 35 in Fig. 1.In Fig. 2, feedback current I
fBagain for current comparator 39 provides forward input.Skew V
oS76, be preferably in the inside of amplifier 38, horizontal transfer feedback voltage V
fB, make it be slightly less than reference voltage V
rEFthereby, make hysteresis comparator 74 under large current condition, its output current is also very large.As feedback current I
fBwhile exceeding the reverse input current that offers current comparator 39, it is large that the output of comparator 39 becomes, and closes the cycle thereby start switch.
Within the cycle of closing, the output 25A of single-shot trigger circuit 25 is very large, and P-MOSFET16 is closed, and N-MOSFET17 opens.After single-shot trigger circuit 25 arranges a time constant, output 25A diminishes, thereby the next one is opened the cycle, and P-MOSFET16 opens and N-MOSFET17 closes.
According to the present invention, voltage regulator circuit 50, under following low output current level, enters sleep pattern.Work as V
fBwhen exceeding a default magnitude of voltage, exceed reference voltage V
rEF, hysteresis comparator 70 is monitored feedback voltage V
fB, and it diminishes.This situation is pointed out output voltage V
oUTexceed a default magnitude of voltage, exceed regulation voltage V
rEG.This deliberately draws an overvoltage in the situation that average output current is very little, so that a constant-current source I to be provided
172, it is coupled in parallel on amplifier 38.Under superpotential condition, MOSFET16 and 17, by AND door 66 and NAND door 68, keeps closing.
Constant-current source I
1for current comparator 39 is provided with a minimum feedback current threshold.The minimum current arranging needs inductance L
1opening cycle internal trigger comparator 39.According to the present invention, when levels of current can trigger, make current comparator 39 be forced to stay open.Therefore, supply with inductance L
1the voltage that produces of electric current be greater than maintenance output voltage V
oUTregulation voltage V
rEG.Make V
oUTincrease, and exceed regulation voltage V
rEG, exceed V in predeterminated voltage value
rEFtime, cause feedback voltage V
fBtrigger hysteresis comparator 74.In the time that comparator 74 triggers, its output diminishes, and to close MOSFET16 and 17, makes voltage regulator circuit enter sleep pattern.
At above-mentioned operating state (, " sleep pattern "), MOSFET16 and 17 closes simultaneously, and output loading 14 is output inductance C
oUTinstitute supports.Hysteresis comparator 74 is monitored feedback voltage V
fB, work as V
oUTdecline, V
fBalso decline because of the sluggishness of comparator 74, drive circuit 20 is jumped out sleep pattern (MOSFET16 and 17 closes), therefore, in a new cycle of opening, thinks that load 14 provides electric current.If it is very low that load current keeps, C
oUTto be charged, make its voltage exceed V
rEF, after the very short cycle, feedback voltage V
fBtrigger comparator 74 again.
Therefore, when load is very little, control circuit 70 is for cutting out MOSFET16 and MOSFET17, in the time of level that they do not need to make output voltage substantially remain on regulation voltage, because output capacitance C
oUTcan accomplish this point.When output voltage reduces, while being less than regulation voltage, under this pattern, what control circuit 70 was of short duration opens switch 15, to output capacitance C
oUTcharging, makes its voltage higher than regulation voltage.Therefore, V
oUTto between upper and lower threshold value, vibrate, it is compared device 74 hysteresis voltages and is multiplied by ratio (R
1+ R
2): R
2institute separates.This ratio " is waken " pressurizer up, is output capacitance C
oUTcharging, until adapt to load current, even when output current is very little, also keeps very high efficiency.
According to the present invention, when output current enough little, to such an extent as to output capacitance C
oUTwhen keeping output voltage to be substantially equal to regulation voltage, during this period of time, control circuit 70 cuts out MOSFET16 and 17.Conventionally,, in the time of closing at this, MOSFET16 and 17 is the state in closing, even, switching regulator provides a regulation voltage, can be from being less than 100 microseconds to several seconds (corresponding respectively to switching frequency is 100KHZ, some switches of ten thousand switch periods of more than ten).This shut-in time allows to obtain very high efficiency (that is, exceeding 90%) conventionally, and output current scope exceedes 100:1.Element except switching transistor, within this time, can keep closing, so, can obtain very high efficiency.
Control circuit 70 in switching regulator 50 shown in Fig. 2, for driving synchronous diverter switch, it comprises MOSFET16 and 17.Used herein, term " synchronous diverter switch " refers to a switch, and it comprises two switching transistors, and the current phase that it is conditioned voltage provides drives, this current direction load.Shown in Fig. 3 is to remove to drive a switch with the second example of efficient control circuit of the present invention, and under pressure-lowering condition, this switch comprises a switching transistor and a switching diode.
As shown in Figure 3, switching regulator circuit 100 comprises switch 115, and it comprises the good diode 118 of P-MOSFET116.Switch 115 is driven by driving 120, drives 120 to comprise that P-drives 126.The opening and closing of switch 115 are controlled by control circuit 125.Because 125 of control circuits are for driving the control circuit 70 of a MOSFET(than Fig. 2), it only has a lead-out terminal 125A(to come from the output of NAND door 68).
Control circuit 125 comprises current comparator 39, amplifier 38, and hysteresis comparator 74 and single-shot trigger circuit 25, be similar to the control circuit 70 shown in Fig. 2.As discussed in Fig. 2, when average output current is very little, constant-current source I
172 are used to deliberately overload drives inductance L
1electric current, cause output voltage V
oUTincrease, exceed regulation voltage V
rEG, during this period of time, output capacitance C
oUTto support output.During this period of time, P-MOSFET116 closes, and enters sleep pattern, to increase circuit efficiency.
As implied above, the control circuit 70 and 125 shown in Fig. 2 and 3, in the situation that average output current is very little, can provide very high efficiency.This operation adapts to output current level automatically.For example, when output current is very large, under first state, the opening and closing that switch replaces, to keep output voltage V
oUTbe substantially equal to regulation voltage V
rEG.When output current is very little, under the second state, current efficiency is very low, output capacitance C
oUTmake output voltage V
oUTbe substantially equal to regulation voltage V
rEG, and do not need constantly to open and close switch.Therefore, the automatic status recognition of control circuit, allows voltage regulator circuit to enter " sleep " pattern, requires element minimum in circuit to open.
According to another feature of the present invention, voltage regulator circuit of the present invention can utilize " user's activation " to carry out control circuit, user's input control and no matter voltage regulator circuit whether in " sleep " state.Shown in Fig. 4 is the theory diagram of switching regulator circuit, and it in conjunction with " user's activation " mode, removes to drive a switch with efficient control circuit of the present invention, and this switch, under pressure-lowering condition, has adopted the switch of a pair of synchro switch MOSFET.
Switching regulator circuit 150 shown in Fig. 4 comprises push-pull switch 15, drives 20, and output circuit 30 is similar to the circuit 50 shown in Fig. 2.The control circuit 170 of voltage regulator circuit 150, comprises single-shot trigger circuit 25, current comparator 39 and amplifier 38, and this is also similar to the circuit 50 in Fig. 2.Than Fig. 2, switch 175(comprises switch 176 and 178) adopt hand switch pressurizer 150, by input, 175A enters sleep state, may obtain control signal from other type of some of control circuit (not showing).Once switch 175 cuts out, switch 176 and 178 also cuts out.
Switch 176 is used to cut out N-and drives 27, enters sleep pattern, and 66(is conventionally very high for ground connection input AND door, is coupled to positive source by resistance 67) input 66A.Switch 178 is used to positive feedback, therefore lags behind and enters amplifier 38, under sleep pattern, allows control circuit 170 to keep output voltage V
oUTbe substantially equal to regulation voltage V
rEG.(resistance R
hYS, be coupling between reference circuit 37 and the positive input of trsanscondutance amplifier 38, for the output of amplifier 38 being fed back to the positive input of amplifier 38).
Switch 178 allows amplifier 38 overloads to drive inductance L
1electric current (passing through P-MOSFET16), with intentional driver output voltage V
oUTenter a default level, exceed regulation voltage V
rEG.After driving reaches this voltage levvl, the sluggishness of amplifier 38 keeps P-to drive 26 to close, until feedback voltage V
fBdecline, at least to hysteresis voltage.Now, the output 39A of current amplifier 39 becomes high level, triggers single-shot trigger circuit 25, to open P-MOSFET16, with to output capacitance C
oUTcharge, make it exceed regulation voltage V
rEG.
As mentioned above, control circuit 170 is waken up at sleep state, opens P-MOSFET16, with to output capacitance C
oUTcharge.In common technology, these are all apparent, under this state waking up, even when N-mOSFET15 keeps closing, will there will not be this situation.For example,, when control circuit 170 is to output capacitance C
oUTwhen charging, this charging, constantly closing switch transistor is realized, and changes duty ratio, thereby to output capacitance C
oUTcharging.
Therefore, in low current situation, voltage regulator circuit 150 is worked, and to raise the efficiency, in the time that user manually boots switch, this is identical with the voltage regulator circuit 50 in Fig. 2.But compared with voltage regulator circuit 50 in Fig. 2, voltage regulator circuit 150 can not adapt to the level of output current automatically.For example, in the time that output current increases, circuit 150 can not make oneself to break away from that sleep pattern-this depends on user's use.
As discussed above, as in Figure 2-4, according to the embodiment of control circuit of the present invention, comprise single-shot trigger circuit 25.According to another feature of the present invention, single-shot trigger circuit can be replaced by the circuit of other types, to control the duty ratio of mains switch.For example, single-shot trigger circuit 25 can be replaced by a pulse width modulation circuit, to provide a pulse width signal to replace control signal.Certainly, also can use the circuit of other types.
According to another feature of the present invention, single-shot trigger circuit 25, provides a constant shut-in time signal, can be provided the single-shot trigger circuit of variable shut-in time control signal to replace by one, and this control signal depends on output voltage (V
oUT) and input voltage (V
iN).This feature of the present invention can make inductance L
1the in the situation that of low input, for the generation and the diffusion that reduce audible noise.As discussed above, these noises are relevant to the vibration of inductive current.In addition, this feature of the present invention, if output short-circuit can be controlled short circuit current.
Shown in Fig. 5 is the theory diagram of switching regulator circuit, and it combines variable shut-in time control circuit of the present invention.
Switching regulator circuit 200 comprises push-pull switch 15, drive circuit 20, current feedback circuit 210, voltage feedback circuit 220, feedback control circuit 230 and variable shut-in time circuit 240.Feedback control circuit 230 monitorings are through output current and the output voltage of input terminal 232 and 234, for terminal 236 provides a triggering signal, with closing the cycle of starting switch 15.Variable shut-in time circuit 240 is for controlling the shut-in time below.
Circuit 240 comprises single generator 245 that triggers, and is fed control circuit 230 triggers by terminal 236.Single generator 245 that triggers comprises an extra terminal 245A, coupling control capacitance (C
cON) 246, its voltage is monitored by generator 245.According to the present invention, shut-in time control circuit 250 control capacitance C
cONelectric discharge, but capacitance voltage is the shut-in time of control generator 245 conversely.Shut-in time control circuit 250 is monitored input and output voltage (V
iNand V
oUT), this depends on their value and the adjustment of shut-in time.
According to the present invention, if input voltage V
iNdecline, inductance L so discussed above
1frequency of oscillation f
rIPalso drop to the scope that can listen, the shut-in time decline time, f
rIPto rise, exceed the scope that can listen.Meanwhile, if output voltage V
oUTbecause short circuit reduces, so, inductance L
1on voltage too low, within the cycle of closing, allow the decay of inductive current, the increase of shut-in time, thereby avoided leakage of current problem.
In this example, control capacitance C
cONelectric discharge by a large amount of control electric current I
cONinstitute regulates.For example, in the situation that input voltage is very low, I
cONbecause shut-in time control circuit 250 increases, cause control capacitance C
cONon voltage fast-descending.The voltage drop of control capacitance, during lower than default value, the cycle of opening of switch 15 starts.In addition, in the situation that output voltage is very low, I
cONbecause shut-in time control circuit 250 reduces, cause control capacitance C
cONon voltage slow-decay, to extend the shut-in time.
Switching regulator 200 as shown in Figure 5, depends on a specific circuit, and in this circuit, capacitor discharge is to control the shut-in time, and clearly, these same functions of other circuit, to respond input and output voltage.For example, if needed, can control the shut-in time with an operational amplifier.
Therefore, discussed above, provide a variable shut-in time control signal with a single-shot trigger circuit, meet the level of input and output voltage.This feature of the present invention, makes voltage regulator circuit when input voltage is very little, and the generation and the diffusion that reduce audible noise (,, under low input, reduce t
oFF), in the time of output short-circuit, limiting short-circuit current (,, under low output voltage, increases t
oFF).
Shown in Fig. 6 is the detailed schematic diagram of variable shut-in time control circuit in Fig. 5.
Shut-in time control circuit 250 receives input V by terminal 252 and 254 respectively
iNand V
oUT, an output I is provided on terminal 256
cON.As discussed above, I
cONcontrol control capacitance C
cONelectric discharge, this control capacitance is coupled on terminal 256.Control circuit 250 is controlled a large amount of I
cON, control capacitance C simultaneously
cONdischarge time.Control circuit 250 comprises that current source 260(provides electric current I
cN2), current source 270(provide electric current I
cN1) current compensation circuit 280 and current mirror output circuit 295.Control circuit 250 operation principles are as follows.
Current mirror output circuit 295 is current mirroring circuits, and it comprises that transistor 296 and its door 298A of transistor 298(are connected to its drain electrode 298B).Circuit 295 receives one at its input 295A and controls reference current I
cREF, and an output current I relevant to transistor 296 and 298 is provided
cON(as traditional current mirroring circuit).According to the present invention, I
cREFequal I
cN1or (I
cN1+ I
cN2), depend on the voltage V on input terminal 252 and 254
iNand V
oUT.
Work as V
iN-V
oUTwhen being greater than 1.5 volts, transistor 262 produces enough electric currents (from transistor 264 and current source I
6) to close transistor 266.In the time that transistor 266 is closed, electric current I
cN2to become zero, electric current I
cREFprovide I by the lead-out terminal 270A that equals current source 270
cN1.
Current mirroring circuit provides an electric current I
cN1, this current mirroring circuit comprises that transistor 272 and its door 274A of transistor 274(are connected to its drain electrode 274B).According to the present invention, from the reference current I of transistor 274
cN1REFequal I
cN1Aor (I
cN1A+ I
cN1B), this depends on opening or closing of transmission gate 282.
Transmission gate 282 is controlled by comparator 284, works as V
oUTbe less than V
tH3time, transmission gate 284 is opened.In the situation that opening, I
cN1REFto equal I
cN1A, to control transistor 276.This electric current is by output voltage V
oUTshunting (being formed by resistance 271 and 273) form, to produce voltage V
fB1(base stage of transistor 279).The base-emitter voltage of transistor 279 makes voltage V
fB1rise, afterwards, due to the base-emitter voltage of transistor 276, make voltage V
fB1decline, this is presented on emitter resistance 278.This makes the collector current of transistor 276 be proportional to output voltage V
oUT, cause control capacitance C
cONthe ratio of electric discharge is proportional to inductance L
1the ratio of electric discharge.
Therefore, work as output voltage V
oUTvery low time, for example, when breaking down or start, t
oFFwill be extended, to allow inductance L
1needed extra time of electric current slow decreasing.
Work as output voltage V
oUTmuch larger than V
tH3time, 282, one extra offset current I of output closing transmission door of comparator 284
cN1Bbe coupled to the drain electrode of transistor 274, by current compensation circuit 280 so that current compensation to be provided.Offset current I
cN1Bequal electric current I
tRIMdeduct the drain current of transistor 286.For the collector current of transistor 290 provides current mirror, (this is similar to the collector current of transistor 276 discussed above, except voltage V with 288 for transistor 286
rEFreplace voltage V
fB1.
Offset current I
cN1Bthere are two objects: 1) work as output voltage V
oUTwithin the limits prescribed time, provide a fine-adjusting current, so that control electric current I to be set substantially
cON; 2), when exceeding the very wide scope of working temperature, keep substantially invariable control electric current I
cON.In the manufacture process of typical circuit, the variation of the resistance value of resistance 278, may cause controlling electric current I
cONlarger or little than the value requiring.In process of production, adjust I
tRIM, can be from the collector current (I of transistor 276
cN1A) suitable increase or deduct offset current I
cN1B, according to demand, provide a default control electric current I
cON.In addition,, if resistance 278 and 292 matches (that is, Design and manufacture is similar), control electric current I
cONchange along with the variation of temperature, due to the change in resistance of resistance 292, the resistance of resistance 278 is cancelled.
If output voltage V
oUTbe less than V
tH3time, transmission gate 282 is opened in the output of comparator 284, suppresses current compensation.This has ensured to work as output voltage V
oUTclose to zero time, control electric current I
cONapproach zero, in output short-circuit, ensure to control inductive current I
l.
Work as V
iNdecline, make V
iN-V
oUTwhen being less than 1.5 volts, the electric current on transistor 262 is no longer closed transistor 266.Work as V
iNwhen continuing to decline, transistor 266 increases extra electric current I for current mirror output circuit 295
cN2thereby, increase and control electric current I
cON, therefore, reduce t
oFF.Work as V
iNwhen decline, this has stablized operating frequency conversely, has reduced potential listened to problem.Current source I
7make the maximum current on transistor 266 add control electric current I
cON.
Therefore, work as V
iNdecline, make V
iN-V
oUTwhen being less than 1.5 volts (, when battery discharge finishes), t
oFFwill reduce, to increase the frequency of oscillation of voltage regulator circuit, thereby reduce generation and the discharge of audible noise.
Variable shut-in time control circuit 250 described above is equivalent to a voltage regulator circuit, and it comprises push-pull switch 15 and driving 20, and feature clearly of variable shut-in time of the present invention, also can be used in other pressurizer.For example, this feature can also be used in the voltage regulator circuit of Fig. 3 and 4, and other circuit adopt single generator that triggers, so that regulation voltage to be provided.
Shown in Fig. 7 is the detailed theory diagram of an exemplary switching regulator circuit, it combines feature and the efficient control circuit of the present invention of shut-in time, to drive a switch, this switch, under pressure-lowering condition, has adopted the switch of a pair of synchro switch MOSFET.
Switching regulator 300 comprises push-pull switch 15, drives 20, output circuit 30 and control circuit 350.Control circuit 350 comprises single generator 245 that triggers, and variable shut-in time control circuit 250, cuts out cycle time to control, and under the condition of very low average output current level, comparator 74 is worked efficiently.Switching regulator 300 working methods are as follows.
In the time that load current transships, for example, 20 percent of about maximum output current, loop works is at continuous mode, and comparator 74 no longer rewrites single output 245A that triggers generator 245.Work as V
iN-V
oUTwhen being greater than 1.5 volts, working condition is described similar to Fig. 1.Inductive current is by resistance R
sENSEon the perception of voltage drop institute, the threshold value of current comparator 39 is by resistance R
3on voltage drop setting.Built-in biasing V
oS(, approximately 10mv), feedback voltage V
fBa little less than reference voltage V
rEF, under this pattern, keep the output of comparator 74 in high potential.Work as resistance R
sENSEon voltage exceed resistance R
3on threshold value, the output of comparator 39 is in high potential, the input RBAR of rest-set flip-flop 310 is electronegative potential, reset rest-set flip-flop 310, starting switch cuts out the cycle.
Within the cycle of closing, switching signal V
sWBfor high potential, close P-MOSFET16, open N-MOSFET17, allow I
cONelectric discharge is to control capacitance C
cON.Shut-in time, t
oFF, conversely by control capacitance C
cONdischarge into V from initial voltage
tH1decide, be coupled to the positive input of comparator 312.Control capacitance C
cONdischarge into V
tH1time, comparator 312 is output as electronegative potential, therefore, rest-set flip-flop 310 is set, and starts the next one and opens the cycle.Voltage V
tH1be greater than voltage V
tH2time, under continuous mode, cause the output of comparator 315 to keep electronegative potential.
According to the present invention, the shut-in time is controlled by the variable shut-in time control circuit 250 of describing in Fig. 5 and 6, and circuit 250 comprises input 252 and 254, V
iNbe coupled to V
oUT, with monitoring voltage.
Current source I
1for the resistance R of current comparator 39
3a minimum voltage threshold is set.Inductance L
1on this minimum current, open in the cycle each, cut off comparator 39.If when flowing to the average inductor current of exporting much larger than load current, output voltage V
oUTto start to rise, cause feedback voltage V
fBcut off hysteresis loop comparator 74.Certainly inductance L,
1inductance value and shut-in time t
oFFselection, preferably, in the time that this cut-out occurs, inductance ripple current is not less than zero.In the time that comparator 74 cuts off, it is output as electronegative potential, rewrites the output Q of rest-set flip-flop 310, switching signal V
sWBbe high potential immediately.As discussed above, this can start the beginning of " sleep " pattern.
Under sleep pattern, capacitor C
cONelectric discharge, in the time that comparator 312 cuts off, does not start the new switch opens cycle.As discussed above, this be because feedback voltage because the hysteresis amount of comparator 74 declines, the low level on lead-out terminal 74A makes switching signal V by NAND door 316
sWBremain on high level.Therefore, control capacitance C
cONcontinue electric discharge, with lower than voltage V
tH2, cause the output 315A of comparator 315 to become high level.This causes N-MOSFET17 and P-MOSFET16 to close conversely.In addition,, when voltage regulator circuit is in sleep pattern time, untapped circuit element, as amplifier 38 and comparator 39 and 312 are also closed.As mentioned above, under sleep pattern, the reduction of bias current, under low output current level, has increased efficiency.
Under sleep pattern, within the shut-in time of singing, most pressurizer MOSFETS16 and 17 closes, and output loading is substantially by output capacitance C
oUTsupply.But, work as output voltage V
oUTwhen decline, feedback voltage V
fBbecause the hysteresis amount on comparator 74 reduces, all circuit elements are opened again, and a new cycle of opening starts, for output provides electric current.If load current is very little, output capacitance C
oUTto charge, after very short switch periods, feedback voltage V
fBtrigger comparator 74 again.Therefore, under light-load conditions, as discussed above, output voltage V
oUTto between upper and lower threshold voltage, vibrate.
In the time that P-MOSFET16 opens, there is grid-source voltage in MOSFET334, to open MOSFET334.This will draw high the drain electrode of MOSFET334, drives 27 to suppress N-.V
sWBtransition from low to high, the gate voltage of P-MOSFET16 must rise to a level, makes MOSFET334 conduction, before the drain voltage of MOSFET334 declines, is less than current source 335, allows N-MOSFET17 to open.Electric current I
m1intentional very little time, before driving use, make the door of MOSFET334, i.e. input voltage V
iNrise to 2 volts, in the time that N-MOSFET17 opens, to guarantee that P-MOSFET closes completely.Use the same method, MOSFET332 and current source I
m2333, when P-MOSFET16 opens, to guarantee that N-MOSFET17 closes completely.This can prevent conducting simultaneously, no matter the size of actuating speed and MOSFET ensures possible maximal efficiency.
As shown in Figure 7, Schottky diode D2 is coupling in around N-MOSFET17, only in the Dead Time between MOSFET16 and 17 conductings, acts on.The effect of diode D2 is that the pipe shaft diode that prevents N-MOSFET17 is opened, and stores electric charge in Dead Time, and (, one of about percentage) under identical condition, may lower efficiency.In the maximum output current of conduction, the pipe that diode D2 preferably selects forward voltage to be less than 0.5 volt.
According to the present invention, control circuit shown in Fig. 7, it may realize the efficiency (input voltage is about 10 volts) that exceedes 90 percent in conjunction with the synchronous buck switching regulator of 5 volts time, it is the variation (, 20mA is to 2A) that output current has two orders of magnitude.Under same condition of work (that is, input voltage is 6 volts), under such levels of current, efficiency can remain on more than 95 percent.This control circuit is particularly suitable for notebook computer and palmtop PC, portable instrument, battery powered digital equipment, mobile phone, DC power supply distribution system and gps system.
As discussed above, with respect to Fig. 1, a shortcoming of control circuit 10 is, under the condition of low output current, and inductance L
1on electric current will be oppositely, if at t
oFFin time, will cause electric current to be very fast that slope declines.This may cause electric power to forget about it ground connection electricity from load, by N-MOSFET17, relative, may reduce circuit efficiency.According to another feature of the present invention, control circuit also comprises a circuit, to close N-MOSFET, in the time that inductive current is reverse, to prevent drawing electric power from load.
Shown in Fig. 8 is the detailed theory diagram of a switching regulator circuit, and it combines circuit of the present invention, and reverse to prevent the electric current on pressurizer outputting inductance, this electric current comes from load.
Switching regulator 400 comprises push-pull switch 15, drive circuit 20 and output circuit 30, and these are all similar to Fig. 1.Circuit 400 also comprises that one according to the embodiment 470 of efficient control circuit of the present invention, to prevent that electric power from load is to outputting inductance L
1the pole reversal of electric current.
Control circuit 470 comprises single-shot trigger circuit 25, current comparator 39 and trsanscondutance amplifier 38, and these are similar to Fig. 1.Except these elements, control circuit 470 also comprises comparator 471 and door 472, under harmonic(-)mean levels of current, to prevent the pole reversal to inductive current from the electric power of load.The working method of control circuit 470 is as follows.
When the lead-out terminal 25A of single-shot trigger circuit becomes high level, close P-MOSFET16, open N-MOSFET17, inductive current I
lstarting to be slope declines.Under the level of harmonic(-)mean output current, this electric current may be slope and drop to zero, even becomes negative value.Control circuit 470 will be monitored inductive current I
l, by current feedback signal I
fB2, before electric current oppositely occurs, close N-MOSFET17.This has stoped N-MOSFET17 to draw electric power from loading to earth point.
Comparator 471 comprises an input terminal 471A, by current feedback signal I
fB2monitoring inductive current I
l.As current feedback signal I
fB2decline, lower than electric current I
4, i.e. electric current on the input terminal 471B of comparator 471, the sub-471C of comparator output terminal becomes low level, by NAND door 472 to close N-MOSFET17.The closing of N-MOSFET17 prevents the electric power from load 104, by N-MOSFET17, makes inductive current I
lthe pole reversal.
After N-MOSFET17 closes, as feedback current I
fB2be greater than electric current I
4, when causing the lead-out terminal 471C of comparator to become high level, N-MOSFET17 will open again.In general, the lead-out terminal 471C of comparator, after single-shot trigger circuit 25 is opened P-MOSFET16, will become high level again, and this causes inductive current I conversely
lagain be on slope and rise.The trend rising on this slope, will make current feedback signal I
fB2be greater than electric current I
4, therefore, cause the sub-471C of comparator output terminal to become high level.In the time that comparator 471C is high level, single-shot trigger circuit 25 is only opened N-MOSFET17.
Therefore, control circuit 470 comprises a circuit, the electric current that this circuit forms at electric power from load may be reverse during, deliberately keep N-MOSFET17 to close.This feature of the present invention, in the time that electric current oppositely occurs, under harmonic(-)mean output current level, can increase current efficiency.
Common technology also can be apparent, even if comparator 471 is by feedback current I
fB2monitor inductive current I
l, also can monitor inductive current I by other mode
lelectric current reverse.For example, comparator 471 can monitoring current feedback signal I
fB1and be applied to any current feedback signal of control circuit 470.In addition, also can produce a feedback signal by other method, to show inductive current I
lelectric current oppositely (, as the R in Fig. 7
sENSE).
With respect to the of the present invention efficient control circuit in above-mentioned discussed Fig. 1-8, switching regulator has a dropping equipment.Clearly, control circuit of the present invention also can be used in other device.For example, shown in Fig. 9 is the detailed theory diagram of a switching regulator circuit, and under the condition of boosting, it combines efficient control circuit of the present invention.
Switching regulator 500 comprise synchronize changer 15 ', together with the drain coupled of P-channel mosfet 16 and N-channel mosfet 17, and be connected to inductance L
1one end.Inductance L
1the other end be coupled to V
iNon.Control circuit 70 be used for driving drive circuit 20 ', this drive circuit comprise reverse P-drive 26 ' and oppositely N-drive 27 ', conversely, drive respectively P-channel mosfet 16 and N-MOSFET17.
Therefore, as shown in Figure 9, control circuit of the present invention can be used in switching device, and this switching device comprises an input voltage V
iN, flow to output end of voltage stabilizer voltage V
oUT.As the dropping equipment of Fig. 2-8, the control circuit of Fig. 9 also can be for the booster type device of other types.For example, the single-shot trigger circuit 25 as shown in 9 comprises an extra input, monitoring input voltage V
iN, as Fig. 5 and Fig. 6 above discuss, make inductance L
1under low input, reduce generation and the discharge of audible noise.Meanwhile, switching regulator 500 also comprises a circuit, and this circuit is at inductive current I
lpolarity may be reverse during, deliberately keep P-MOSFET16 to close, as the situation that Fig. 8 discussed above.
Shown in Figure 10 is the detailed theory diagram of a switching regulator circuit, and under the reverse condition of polarity of voltage, it combines efficient control circuit of the present invention.
Switching regulator 600 comprises switch 15 ", the drain coupled of P-channel mosfet 16 is to inductance L
1one end, by diode, D601 is connected to V
oUT.Inductance L
1the other end be coupled to earth point.The source-coupled of P-channel mosfet 16 is to input voltage V
iNpositive pole.Control circuit 70 ' be used for driving drive circuit 20 ", this drive circuit comprises that reverse P-drives 26, conversely, drives P-channel mosfet 16.
Control circuit 70 ' working method similar to above-mentioned discussed control circuit 70.Control circuit 70 ' Voltage Feedback by resistance R
1and R
2, amplifier 602 provides.Amplifier 602 is by V
oUTcathode voltage reverse, with provide cathode voltage to control circuit 70 '.
Therefore, as shown in figure 10, control circuit of the present invention can be used in switching device, and this switching device comprises an input voltage V
iN, it converts stabilizer output voltage to contrary polarity V
oUT.As the dropping equipment of Fig. 2-8, the control circuit of Figure 10 also can be for the device of the pole reversal of other types.For example, the single-shot trigger circuit 25 as shown in 10 comprises an extra input, monitoring input voltage V
iN, make inductance L
1under low input, reduce generation and the discharge of audible noise.Meanwhile, single-shot trigger circuit 25 also comprises an input, to monitor output voltage V
oUT, as illustrated in Figures 5 and 6, if when output short-circuit, to control short circuit current.Equally, if pressurizer 600 is synchro switches, it comprises a N-MOSFET, and to replace D601, this pressurizer also comprises a circuit, and this circuit is at inductive current I
lpolarity may be reverse during, deliberately keep N-MOSFET to close, as the situation that Fig. 8 discussed above.
Common technology also can be apparent, technology of the present invention as discussed above, with reference to the synchronizing voltage comparator of sleep mode control signal, cause switching regulator to enter and walk out sleep pattern, also can use the additive method that can show identical function.For example, if needed, sleep mode control signal can be made response to the output current of monitoring.In addition, switching regulator, after entering sleep pattern, can depart from a predetermined time of sleep pattern, discussed above after output voltage declines, lower than predetermined threshold voltage to replace.
Obviously, technology of the present invention as discussed above, with reference to Fig. 1-10, power switch is that a pair of Complementary MOSFET S(is, a P-raceway groove and a N-raceway groove) or a signal P-channel mosfet (Fig. 3), the present invention also can use the switch of other types.For example, power switch can comprise a pair of N-channel mosfet S, a pair of P-channel mosfet S or bipolar transistor.
Therefore, provide a kind of switching regulator, it keeps high efficiency control circuit and method under very wide current range.
The principle according to the present invention, people can find, and it can also be applied to other circuit, and for purposes of illustration, the present invention is unrestricted, limited by claim of the present invention.
Claims (9)
1. a switching regulator, it is characterized in that: the circuit of control switch Voltagre regulator, the electric current output that comprises a switch and a reference voltage is applicable to a load, this load comprises an output capacitance, switch is coupling between input voltage and output voltage, also comprise one or more switching transistors, this circuit comprises: the first circuit of monitoring output, to produce first feedback signal; At circuit working during the first state, second circuit produces the first control signal, second circuit comprises single-shot trigger circuit, produces the first control signal, in time first period, keep in the situation of regulation voltage output, " opening " and " pass " of controlling one or more switching transistor, single-shot trigger circuit is triggered, to respond the first feedback signal, time first period, at least respond one of them of input voltage and output voltage.
2. a kind of switching regulator according to claim 1, is characterized in that: time first period, response input voltage; Switch is coupled on an inductance; The minimizing of time first period is the response that reduces to make to input voltage; Audible frequency has increased the frequency of oscillation of inductance ripple current, but does not produce user's audible noise; Time first period, response output voltage; Switch is coupled on an inductance; The minimizing of time first period is the response that reduces to make to input voltage; In the time producing the first control signal, inductive current entirety decrease increases; This circuit also comprises an inductance, and it is coupling on single-shot trigger circuit, the variable current source of control capacitance discharge rate, and discharge rate is at least made response to one in input voltage and output voltage, to control time first period.
3. a kind of switching regulator according to claim 2, is characterized in that: time first period, response input voltage; Switch is coupled on an inductance; The minimizing of time first period is the response that reduces to make to input voltage; Audible frequency has increased the frequency of oscillation of inductance ripple current, but does not produce user's audible noise; Time first period, response output voltage; Switch is coupled on an inductance; The minimizing of time first period is the response that reduces to make to input voltage; In the time producing the first control signal, inductive current entirety decrease increases.
4. a kind of switching regulator according to claim 1, it is characterized in that: a switching voltage pressurizer produces an output on output node, on input node, produce an input, output node is coupled in output capacitance, pressurizer comprises: a switching transistor has a first terminal, it is coupled on input node, second terminal and the 3rd terminal; A drive circuit has a first terminal, second terminal, and it is coupled on the second terminal of switching transistor; An inductance, has a first terminal, and it is coupled on the 3rd terminal of switching transistor, and its second terminal is coupled on output node; A feedback circuit has a first terminal, and it is coupled on output node, and second terminal, and feedback circuit produces a feedback signal on the second terminal of feedback circuit; A feedback control circuit, have a first terminal, it is coupled on the second terminal of feedback circuit, and second terminal, feedback control circuit produces a triggering signal on the second terminal of feedback control circuit, and triggering signal is the response that feedback signal is made; A shutdown control circuit, has a first terminal and second terminal, and shutdown control circuit produces one and closes machine control signal on its first terminal, and the second terminal of shutdown control circuit is coupling in one of them of input node or output node; Single generator that triggers, there is a first terminal, it is coupled on the second terminal of feedback control circuit, it has second terminal, be coupled on the first terminal of shutdown control circuit, it also has the 3rd terminal, be coupled on the first terminal of drive circuit, single generator that triggers produces a switching signal on its 3rd terminal, once receive triggering signal, driving makes switching transistor enter closed condition, continues in time first period always, and this time determines by closing machine control signal.
5. a kind of switching regulator according to claim 4, is characterized in that: feedback circuit produces a voltage feedback signal on its second terminal; Feedback circuit produces a current feedback signal on its second terminal; Pressurizer also comprises: a voltage feedback circuit, it has a first terminal, be coupled on output node, second terminal, voltage feedback circuit produces a voltage feedback signal on its second terminal, and feedback control circuit has the 3rd terminal, is coupled on the second terminal of voltage feedback circuit, the generation of triggering signal is the response that current feedback signal and voltage feedback signal are made; The second terminal of shutdown control circuit, is coupled on input node, closes the generation of machine control signal, is the response that the voltage on input node and time first period are made; Shutdown control circuit produces one and closes machine control signal, to reduce time first period, to reducing of voltage on input node, makes response, and audible frequency has increased the frequency of oscillation of inductance ripple current; The second terminal of shutdown control circuit is coupling on output node, closes the generation of machine control signal, is the response that the voltage on output node and time first period are made; Shutdown control circuit produces one and closes machine control signal, to increase time first period, to reducing of voltage on output node, makes response; The second terminal of shutdown control circuit, be coupled on input node, shutdown control circuit also comprises the 3rd terminal, is coupled on output node, closing the generation of machine control signal, is the response that the voltage on input node and output node and time first period are made; Single generator that triggers comprises a control capacitance, is coupling between single the second terminal and earth point that triggers generator, and shutdown control circuit comprises a variable current source, to control the discharge rate of control capacitance; The second terminal of shutdown control circuit, is coupled on output node, the discharge rate of variable current source control control capacitance, the response that the voltage to input on node and time first period are made; The discharge rate of variable current source control control capacitance, reducing of time first period, is the response that reduces to make to the voltage on input node, and audible frequency has increased the frequency of oscillation of inductance ripple current, and this frequency be can't hear substantially; The second terminal of shutdown control circuit, is coupled on output node, the discharge rate of variable current source control control capacitance, the response that the voltage on output node and time first period are made; The discharge rate of variable current source control control capacitance, the increase of time first period, is the response that reduces to make to the voltage on output node; The second terminal of shutdown control circuit, be coupled on input node, shutdown control circuit also comprises the 3rd terminal, is coupled on output node, the discharge rate of variable current source control control capacitance, the response that the voltage on input node and output node and time first period are made; Shutdown control circuit comprises a control circuit, and it produces one and controls electric current, to control variable current source, and the response that the voltage on input node and output node and time first period are made; Control circuit comprises: first current source, provides the first electric current; Second current source, provides second electric current; A current compensation circuit; A current mirror output circuit, electric current is controlled in output; Current mirror output circuit, produces an electric current being directly proportional to the first electric current, or the first electric current and the second electric current sum, and its value depends on input node voltage and output node voltage; When the input voltage of node and the voltage difference of output node are during much larger than default value, the second current source makes the second electric current vanishing; When the input voltage of node and the voltage difference of output node are during much smaller than default value, the increase of the second electric current, is to the reducing of voltage on input node, the response of making; Current compensation circuit regulates controls electric current, with the variation of compensation temperature.
6. a kind of switching regulator according to claim 1, it is characterized in that: control switch voltage regulator circuit has the electric current output of a switch and a regulation voltage to be applicable to a load, this load comprises an output capacitance, switch is coupling between input voltage and output voltage, it also comprises one or more switching transistors, and this circuit comprises: the terminal of generation current feedback signal; Produce the terminal of voltage feedback signal; Produce the terminal of triggering signal, so that current feedback signal and voltage feedback signal are made to response; Produce the terminal that closes machine control signal, at least make response to one in input voltage and output voltage; Single trigger terminal, makes switch enter closed condition, and so that triggering signal is made to response, switch keeps the state of cutting out within a period of time, to make response to closing machine control signal.
7. a kind of switching regulator according to claim 6, is characterized in that: pass machine control signal the reducing within a period of time producing on terminal is that input voltage reduced to make response; The increase of the pass machine control signal producing on terminal within a period of time is that output voltage reduced to make response.
8. a kind of switching regulator according to claim 1, it is characterized in that: switching voltage pressurizer has an output node and an input node, output node is coupled in output capacitance, pressurizer comprises: a switching transistor, it has a first terminal, be coupled on input node second terminal and the 3rd terminal; A drive circuit has a first terminal, second terminal, and it is coupled on the second terminal of switching transistor; An inductance, has a first terminal, and it is coupled on the 3rd terminal of switching transistor, and its second terminal is coupled on output node; A feedback circuit has a first terminal, and it is coupled on output node, and second terminal; Single generator that triggers, there is a first terminal, it is coupled on the second terminal of feedback control circuit, it has second terminal, it also has the 3rd terminal, be coupled on the first terminal of drive circuit, single generator that triggers comprises a control capacitance, and it is coupling between single the second terminal and earth point that triggers generator; A shutdown control circuit, has a first terminal, is coupling on single the second terminal that triggers generator, it also has second terminal, be coupling in one of them of input node and output node, shutdown control circuit comprises a variable current source, to control the discharge rate of control capacitance.
9. a kind of switching regulator according to claim 8, is characterized in that: feedback circuit comprises a voltage feedback circuit; Feedback circuit comprises a current feedback circuit; Pressurizer also comprises: a voltage feedback circuit, and it has a first terminal, is coupled on output node, second terminal, feedback control circuit has the 3rd terminal, is coupled on the second terminal of voltage feedback circuit; Shutdown control circuit also comprises second terminal, and it is coupling on input node, closes the generation of machine control signal, is voltage and time first period on input node are made to response; The second terminal of shutdown control circuit is coupled on input node; The second terminal of shutdown control circuit is coupled on output node; Shutdown control circuit also comprises the 3rd terminal, and it is coupled on output node.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320763879.6U CN203813658U (en) | 2013-11-27 | 2013-11-27 | Switching voltage regulator |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320763879.6U CN203813658U (en) | 2013-11-27 | 2013-11-27 | Switching voltage regulator |
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| CN203813658U true CN203813658U (en) | 2014-09-03 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103618447A (en) * | 2013-11-27 | 2014-03-05 | 苏州贝克微电子有限公司 | Switching regulator |
| CN107229303A (en) * | 2016-03-23 | 2017-10-03 | 株式会社巨晶片 | The control method of the output voltage of signal generating apparatus and voltage-stablizer |
| WO2020048077A1 (en) * | 2018-09-08 | 2020-03-12 | Shenzhen GOODIX Technology Co., Ltd. | Ripple detection and cancellation for voltage regulator circuits |
-
2013
- 2013-11-27 CN CN201320763879.6U patent/CN203813658U/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103618447A (en) * | 2013-11-27 | 2014-03-05 | 苏州贝克微电子有限公司 | Switching regulator |
| CN107229303A (en) * | 2016-03-23 | 2017-10-03 | 株式会社巨晶片 | The control method of the output voltage of signal generating apparatus and voltage-stablizer |
| WO2020048077A1 (en) * | 2018-09-08 | 2020-03-12 | Shenzhen GOODIX Technology Co., Ltd. | Ripple detection and cancellation for voltage regulator circuits |
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