CN203206119U - Switching converter - Google Patents
Switching converter Download PDFInfo
- Publication number
- CN203206119U CN203206119U CN 201320109062 CN201320109062U CN203206119U CN 203206119 U CN203206119 U CN 203206119U CN 201320109062 CN201320109062 CN 201320109062 CN 201320109062 U CN201320109062 U CN 201320109062U CN 203206119 U CN203206119 U CN 203206119U
- Authority
- CN
- China
- Prior art keywords
- output
- input
- signal
- coupled
- receives
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Images
Abstract
The utility model discloses a switching converter. The switching converter comprises: a power level circuit comprising a power switch, wherein the power level circuit is used to convert an input voltage into an output voltage; a current detection circuit for providing a current detection signal which is representative of the current flowing through the power switch; a pulse width modulation (PWM) controller for outputting a PWM signal; a switch-off time controller for outputting a switch-off time control signal; and a logic circuit for outputting an on-off control signal to control the switch-on and switch-off of the power switch. According to the switching converter, the system efficiency is improved, the current control and overcurrent protection are more accurate, and at the same time the system is more stable.
Description
Technical field
The utility model relates to a kind of electronic circuit, and more particularly, the utility model relates to a kind of dc-dc converter
Background technology
Dc-dc converter is generally used for providing power supply to electronic equipment.Generally speaking, have inductance or transformer in the dc-dc converter as energy-storage travelling wave tube.For example, step-down switching-converter employing inductance is energy-storage travelling wave tube.Described inductance and power switch couple.When the power switch conducting, described inductance storage power; When power switch turn-offed, energy stored was transferred to load in the inductance.
The dc-dc converter of peak current control detects the electric current that flows through energy-storage travelling wave tube when operate as normal, should detect electric current and be incorporated in the control loop, therefore has fairly simple dynamic cyclic system.The greatest drawback of the dc-dc converter of peak current control is that described detection electric current is interfered easily.Duty ratio at dc-dc converter surpasses in 50%, and this interference will make system produce subharmonic oscillation, cause the instability of system.Be the stability problem of resolution system, the dc-dc converter of peak current control is introduced slope compensation usually in current controlled circuit.
Fig. 1 is the signal waveform schematic diagram in the dc-dc converter of existing peak current control.Vs has characterized the inductive current detection signal, and Ipeak has characterized peak-current signal, and Vsp has characterized through the peak-current signal behind the slope compensation.As shown in Figure 1, in each switch periods, when the power switch conducting, inductive current detection signal Vs rises; When inductive current detection signal Vs rose to through the peak-current signal Vsp behind the slope compensation, power switch turn-offed, and inductive current detection signal Vs is reduced.As can be seen from Figure 1, inductive current detection signal Vs begins to reduce when rising to through the peak-current signal Vsp behind the slope compensation, can't rise to real peak-current signal Ipeak, thereby cause the existence of error, influence the accuracy of system's loop control.
The utility model content
The purpose of this utility model is to solve the above-mentioned technical problem of prior art, proposes a kind of dc-dc converter of duration control that turn-offs to realize accurate peak current control.
According to embodiment of the present utility model, a kind of dc-dc converter has been proposed, comprising: power stage circuit, comprise power switch, described power stage circuit converts input voltage to output voltage; Current detection circuit is coupled to power stage circuit, and described output provides the current detection signal that characterizes the electric current that flows through power switch; Error amplifier, have first input end, second input and output, described first input end receives the feedback signal that characterizes output voltage, described second input receives first reference signal, based on described feedback signal and first reference signal, described error amplifier is exported compensating signal at output; Pulse width modulation (PWM) comparator, have first input end, second input and output, described first input end is coupled to current detection circuit received current detection signal, described second input is coupled to error amplifier and receives compensating signal, based on described current detection signal and compensating signal, described PWM comparator is at the output output pwm signal; Turn-off the duration controller, have first input end, second input and input, wherein said first input end receives input voltage, and described second input receives output voltage, based on input voltage and output voltage, described shutoff duration controller turn-offs the duration control signal in output output; And logical circuit, have first input end, second input and output, the output that wherein said first input end is coupled to the PWM controller receives pwm signal, described second input is coupled to the output that turn-offs the duration controller and receives shutoff duration control signal, based on pwm signal and shutoff duration control signal, described logical circuit is controlled the break-make of power switch at the output output switch control signal.
In one embodiment, described dc-dc converter, also comprise: current foldback circuit, have first input end, second input and output, wherein said first input end is coupled to current detection circuit received current detection signal, described second input receives peak-current signal, described output output overcurrent guard signal; Wherein, described logical circuit also has the 3rd input, and the output that described the 3rd input is coupled to current foldback circuit receives the overcurrent protection signal, and described output output switch control signal is controlled the break-make of power switch.
In one embodiment, described shutoff duration controller comprises: first current source provides the charging current that is directly proportional with input voltage; First electric capacity has first end and second end, and described first end is coupled to first current source and receives charging current, the described second end ground connection; First switch has first end, second end and control end, and described first end is coupled to first current source, the described second end ground connection, and described control end is coupled to the output receiving key control signal of logical circuit; And turn-off duration and control comparator, have first input end, second input and output, first termination that wherein said first input end is coupled to first electric capacity is received the voltage on the electric capacity on the, second reference signal that the described second input reception is directly proportional with the difference of input voltage and output voltage, described shutoff duration control comparator turn-offs the duration control signal in output output.
In one embodiment, described dc-dc converter also comprises reference signal generator, described reference signal generator produces first reference signal, comprise: index signal generator, have output, described output output has the exponential signal of exponential function waveform; The linear signal generator has output, and described output output device has the linear signal of linear gradient; And selection circuit, have first input end, second input and output, the output that described first input end is coupled to index signal generator receives exponential signal, the output that described second input is coupled to the linear signal generator receives linear signal, described selection circuit at the smaller value of output output index signal and linear signal as first reference signal.
According to embodiment of the present utility model, a kind of dc-dc converter has also been proposed, comprising: power stage circuit, comprise power switch, described power stage circuit has input and output, and described input receives input voltage, and described output provides output voltage; Current detection circuit has input and output, and described input is coupled to power stage circuit, and described output provides the current detection signal that characterizes the electric current that flows through power switch; The PWM controller has first input end, second input and output, and wherein said first input end receives the feedback signal of the output voltage that characterizes dc-dc converter, the described second input received current detection signal, described output output pwm signal; Turn-off the duration controller, have first input end, second input and input, the input voltage of wherein said first input end receiving key transducer, the output voltage of the described second input receiving key transducer, the duration control signal is turn-offed in described output output; And logical circuit, have first input end, second input and output, the output that wherein said first input end is coupled to the PWM controller receives pwm signal, described second input is coupled to the output that turn-offs the duration controller and receives shutoff duration control signal, and described output output switch control signal is controlled the break-make of power switch.
In one embodiment, described dc-dc converter also comprises current foldback circuit, have first input end, second input and output, wherein said first input end is coupled to current detection circuit received current detection signal, described second input receives peak-current signal, described output output overcurrent guard signal; Wherein, described logical circuit also has the 3rd input, and the output that described the 3rd input is coupled to current foldback circuit receives the overcurrent protection signal, and described output output switch control signal is controlled the break-make of power switch.
In one embodiment, described shutoff duration controller comprises: first current source provides the charging current that is directly proportional with input voltage; First electric capacity has first end and second end, and described first end is coupled to first current source and receives charging current, the described second end ground connection; First switch has first end, second end and control end, and described first end is coupled to first current source, the described second end ground connection, and described control end is coupled to the output receiving key control signal of logical circuit; And turn-off duration and control comparator, have first input end, second input and output, first termination that wherein said first input end is coupled to first electric capacity is received the voltage on first electric capacity, second reference signal that the described second input reception is directly proportional with the difference of input voltage and output voltage, described shutoff duration control comparator turn-offs the duration control signal in output output.
In one embodiment, described dc-dc converter also comprises reference signal generator, and described reference signal generator produces first reference signal, comprising: index signal generator, have output, and described output output has the exponential signal of exponential function waveform; The linear signal generator has output, and described output output device has the linear signal of linear gradient; And selection circuit, have first input end, second input and output, the output that described first input end is coupled to index signal generator receives exponential signal, the output that described second input is coupled to the linear signal generator receives linear signal, described selection circuit at the smaller value of output output index signal and linear signal as first reference signal.
Above-mentioned dc-dc converter according to the utility model each side has improved system effectiveness, makes Current Control and overcurrent protection more accurate, also makes system more stable simultaneously.
Description of drawings
In order better to understand the utility model, will be described embodiment of the present utility model according to the following drawings:
Fig. 1 is the signal waveform schematic diagram in the dc-dc converter of existing peak current control;
Fig. 2 is the circuit block diagram according to the dc-dc converter 200 of the utility model one embodiment;
Fig. 3 is the electrical block diagram according to the dc-dc converter 300 of the utility model one embodiment;
Fig. 4 is the electrical block diagram according to the dc-dc converter 400 of the utility model one embodiment;
Fig. 5 is the electrical block diagram for generation of the reference signal generator of the first reference signal Vref1 according to the utility model one embodiment;
Fig. 6 is the waveform schematic diagram according to the first reference signal Vref1 of the utility model one embodiment;
Fig. 7 is the electrical block diagram according to the reference signal generator 70 of the utility model one embodiment.
Accompanying drawing does not show all circuit or the structure of embodiment.Run through institute's identical Reference numeral of drawings attached and represent same or analogous parts or feature.
Embodiment
To describe specific embodiment of the utility model in detail below, should be noted that the embodiments described herein only is used for illustrating, be not limited to the utility model.In the following description, in order to provide thorough understanding of the present utility model, a large amount of specific detail have been set forth.Yet, it is evident that for those of ordinary skills: needn't adopt these specific detail to carry out the utility model.In other examples, for fear of obscuring the utility model, do not specifically describe known circuit, material or method.
In whole specification, " embodiment ", " embodiment ", " example " or mentioning of " example " are meaned: special characteristic, structure or characteristic in conjunction with this embodiment or example description are comprised among at least one embodiment of the utility model.Therefore, differ to establish a capital in each local phrase " in one embodiment ", " in an embodiment ", " example " or " example " that occurs of whole specification and refer to same embodiment or example.In addition, can with any suitable combination and/or sub-portfolio with specific feature, structure or property combination in one or more embodiment or example.In addition, it should be understood by one skilled in the art that at this accompanying drawing that provides all be for illustrative purposes, and accompanying drawing is drawn in proportion not necessarily.Should be appreciated that when claiming element " to be couple to " or during " being connected to " another element, it can be directly to couple or be couple to another element or can have intermediary element.On the contrary, when claiming element " to be directly coupled to " or during " being directly connected to " another element, not having intermediary element.Identical Reference numeral indication components identical.Term used herein " and/or " comprise any and all combinations of one or more relevant projects of listing.
Fig. 2 is the circuit block diagram according to the dc-dc converter 200 of the utility model one embodiment.As shown in Figure 2, dc-dc converter 200 comprises: power stage circuit 201, comprise power switch M0, and described power stage circuit 201 converts input voltage VIN to output voltage VO UT; Current detection circuit 202 is coupled to power stage circuit 201, and described output provides the current detection signal Vs that characterizes the electric current that flows through power switch M0; PWM (pulse width modulation) controller 203, have first input end, second input and output, wherein said first input end receives the feedback signal VFB that characterizes output voltage VO UT, the described second input received current detection signal Vs, based on feedback signal VFB and current detection signal Vs, described PWM controller 203 is at output output pwm signal Vp; Turn-off duration controller 204, have first input end, second input and output, wherein said first input end receives input voltage VIN, described second input receives output voltage VO UT, based on input voltage VIN and output voltage VO UT, described shutoff duration controller 204 turn-offs duration control signal AOFF in output output; Logical circuit 205, have first input end, second input and output, the output that wherein said first input end is coupled to PWM controller 203 receives pwm signal Vp, described second input is coupled to the output that turn-offs duration controller 204 and receives shutoff duration control signal AOFF, based on pwm signal and shutoff duration control signal AOFF, described logical circuit is controlled the break-make of power switch M0 at output output switch control signal SW.
In another embodiment; described dc-dc converter 200 can also comprise current foldback circuit 206; have first input end, second input and output; wherein said first input end received current detection signal Vs; described second input receives peak-current signal Ipeak; based on current detection signal Vs and peak-current signal Ipeak, described current foldback circuit 206 is at output output overcurrent guard signal Vocp.In one embodiment; described logical circuit 205 can also have the 3rd input; the output that described the 3rd input is coupled to current foldback circuit 206 receives overcurrent protection signal Vocp; based on pwm signal Vp, shutoff duration control signal AOFF and overcurrent protection signal Vocp, described logical circuit 205 is controlled power switch M0 at output output switch control signal SW.
Those of ordinary skills should be understood that described power stage circuit 201 may have various topological structures, for example adjusting and voltage-reduction switch topology, booster type switch topology, flyback switching topology etc.Power switch in the power stage circuit 201 can comprise any controllable semiconductor device, for example metal oxide semiconductor field effect tube, insulated gate gate pole transistor, triode etc.
Anyly can be used for detecting the circuit that flows through power switch M0, current sense resistor for example, current mirror, current transformer etc. can be used as current detection circuit 202.
In one embodiment, turn-off the shutoff duration of duration control signal AOFF control power switch M0, set the minimum turn-off duration of power switch M0.
In dc-dc converter, switching frequency fixedly has the plurality of advantages such as filter circuit design of simplifying dc-dc converter.For the switching frequency that makes dc-dc converter 200 is fixed, has specific relation between shutoff duration, input voltage and the output voltage of power switch.
When power stage circuit 201 had the voltage-dropping type topology, if the switching frequency that is fixed, its output voltage was:
Wherein Toff characterizes the shutoff duration of power switch, and D characterizes the duty ratio of dc-dc converter 200, and T characterizes the switch periods of dc-dc converter.Can obtain turn-offing duration from formula (1) is:
From formula (2), as can be seen, for when the input voltage of dc-dc converter 200 and output voltage change, still make the switching frequency of circuit constant, even switch periods T is constant, turn-off duration Toff value should with
Be directly proportional.That is to say that the shutoff duration Toff that turn-offs the power switch of duration controller 204 controls needs to be directly proportional with the difference VIN-VOUT of input voltage and output voltage, and is inversely proportional to input voltage VIN.
When power stage circuit 201 had the booster type topology, for the switching frequency that is fixed, its output voltage was:
Can obtain turn-offing duration from formula (3) is:
From formula (4), as can be seen, for when the input voltage of dc-dc converter 200 and output voltage change, still make the switching frequency of circuit constant, make that namely switch periods T is constant, turn-off duration Toff value should with
Be directly proportional.That is to say that the shutoff duration Toff that turn-offs the power switch of duration controller 204 controls needs to be directly proportional with input voltage VIN, and is inversely proportional to output voltage VO UT.
Those of ordinary skills can be according to above derivation, when obtaining power stage circuit 201 and having other topological structure, turn-offs the relation between duration and input voltage and output voltage.Because in the dc-dc converter 200, the shutoff duration Toff of power switch is variable, therefore can produce subharmonic oscillation as the dc-dc converter of traditional peak current control, thereby just not need slope compensation yet.Dc-dc converter according to the utility model embodiment has improved system effectiveness, makes Current Control and overcurrent protection more accurate, also makes system more stable simultaneously.
Fig. 3 is the electrical block diagram according to the dc-dc converter 300 of the utility model one embodiment.As shown in Figure 3, dc-dc converter 300 comprises: power stage circuit 301, current detection circuit 302, PWM controller 303, current foldback circuit 306, shutoff duration controller 304 and logical circuit 305.
In circuit shown in Figure 3, power stage circuit 301 has the voltage-dropping type topological structure.Power stage circuit 301 comprises power switch M1, diode D1, inductance L 1 and the output capacitance Co that couples with schematic structure.
In one embodiment, PWM controller 303 comprises: error amplifier 3031, have first input end (inverting input), second input (normal phase input end) and output, described first input end receives the feedback signal VFB that characterizes output voltage VO UT, described second input receives the first reference signal Vref1, based on described feedback signal VFB and the first reference signal Vref1, described error amplifier 3031 is at output output compensating signal Vcom; And PWM comparator 3032, have first input end (normal phase input end), second input (negative input) and output, described first input end is coupled to current detection circuit 302 received current detection signal Vs, described second input is coupled to error amplifier 3031 and receives compensating signal Vcom, based on described current detection signal Vs and compensating signal Vcom, described PWM comparator 3032 is at output output pwm signal Vp.
In one embodiment; described current foldback circuit 306 comprises comparator; described comparator has first input end (normal phase input end), second input (inverting input) and output; wherein said first input end is coupled to current detection circuit 302 received current detection signal Vs; described second input receives peak-current signal Ipeak; based on described current detection signal Vs and peak-current signal Ipeak, described current foldback circuit 306 is at output output overcurrent guard signal Vocp.When the value of current detection signal Vs increased to compensating signal Vcom or peak-current signal Ipeak, described power switch M1 turn-offed.
In one embodiment, described shutoff duration controller 304 comprises: the first current source I1 provides the charging current that is directly proportional with input voltage VIN; First capacitor C 1 has first end and second end, and described first end is coupled to the first current source I1 and receives charging current, the described second end ground connection; The first switch M2 has first end, second end and control end, and described first end is coupled to the first current source I1, the described second end ground connection, and described control end is coupled to the output receiving key control signal SW of logical circuit 305; And turn-off duration and control comparator 3041, have first input end (normal phase input end), second input (inverting input) and output, wherein said first input end is coupled to first end of first capacitor C 1, described second input receives the second reference signal Vref2, the described second reference signal Vref2 is directly proportional with the difference of input voltage and output voltage, based on the voltage on first capacitor C 1 and the second reference signal Vref2, described shutoff duration control comparator 3041 turn-offs duration control signal AOFF in output output.
In one embodiment, the value of the charging current that the described first current source I1 provides is K1 * VIN, and the value of the described second reference signal Vref2 is that K2 * (VIN-VOUT), wherein K1 and K2 are constant.In one embodiment, when power switch M1 turn-offs, the described first switch M2 conducting; When power switch M1 conducting, the described first switch M2 turn-offs.
In one embodiment, described logical circuit 305 comprises: OR circuit OR1, have first input end, second input and output, wherein said first input end is coupled to PWM controller 303 and receives pwm signal Vp, described second input is coupled to current foldback circuit 306 and receives overcurrent protection signal Vocp, based on described pwm signal Vp and overcurrent protection signal Vocp, described OR circuit OR1 is at output output reset signal VR; And rest-set flip-flop FF1, have reset terminal, set end and output, the output that wherein said reset terminal is coupled to OR circuit OR1 receives reset signal VR, described set end is coupled to and turn-offs duration controller 304 reception shutoff duration control signal AOFF, based on described reset signal VR and shutoff duration control signal AOFF, described rest-set flip-flop is at output output switch control signal SW.
Those of ordinary skills should be understood that in the dc-dc converter that does not have current foldback circuit 306, OR circuit OR1 can be omitted, and the reset terminal of rest-set flip-flop FF1 is coupled to the output of PWM controller 303.
In one embodiment, the course of work of dc-dc converter 300 is: when shutoff duration control signal AOFF was logic high, rest-set flip-flop FF1 was set, power switch M1 conducting.At this moment, input voltage VIN is coupled to inductance L 1, provides electric energy to load, and the value of current detection signal Vs rises.Simultaneously, the first switch M2 will be switched on, and the voltage Vc1 on first capacitor C 1 descends, and make to turn-off 3041 upsets of duration control comparator, the shutoff duration control signal AOFF of output low level.When the value of current detection signal Vs rose to compensating signal Vcom, rest-set flip-flop FF1 was reset, and described power switch M1 turn-offs.As indicated above, the shutoff duration Toff of power switch M1 determines by turn-offing duration controller 304.When the shutoff duration control signal AOFF that turn-offs 304 outputs of duration controller became logic high again, rest-set flip-flop FF1 was set, power switch M1 conducting, and the above course of work moves in circles.
Fig. 4 is the electrical block diagram according to the dc-dc converter 400 of the utility model one embodiment.Dc-dc converter 400 can be used for hot plug.Hot plug refers in shutdown system not, takes out and change the parts such as hard disk, power supply or integrated circuit board that damage under the situation of not cutting off the electricity supply.Dc-dc converter 400 may be coupled between power-supply system and the miscellaneous equipment.In one embodiment, when being inserted into equipment on the power supply when system's operate as normal, dc-dc converter 400 is started working.Dc-dc converter 400 the startup stage, the duty ratio of the power switch M1 in the dc-dc converter 400 little by little begins to increase to 100% by 0, thereby suppresses surge current and protection power-supply system and equipment.After the startup of dc-dc converter 400 was finished, the duty ratio of power switch M1 remained 100%, made energy directly be transferred to equipment from power-supply system.
Except the structure of power stage circuit 401, other circuit structure of dc-dc converter 400 is consistent with the circuit structure of dc-dc converter 300.In the embodiment of Fig. 4, current detection circuit 402 comprises the current sense resistor Rs that is coupled between power switch M1 and the ground.The electric current that flows through power switch M1 also flows through current sense resistor Rs simultaneously, thereby forms pressure reduction at resistance R s two ends, is current detection signal Vs.
As can be seen from Figure 4, since the value of feedback signal VFB by the value of Pliers to the first reference signal Vref1.Therefore, output voltage VO UT has the similar waveform with the first reference signal Vref1.When dc-dc converter 400 was used for hot plug, when equipment was inserted into power-supply system, the output voltage VO UT of dc-dc converter 400 should progressively rise, and finally equaled input voltage VIN.Therefore, the first reference signal Vref1 need be since 0 waveform that progressively rises to control output voltage VO UT.When output voltage VO UT equaled input voltage VIN, the slope of the first reference signal Vref1 was 0, and the duty ratio of power switch M1 is 100%.Correspondingly, the electric current that flows through inductance L 1 also equals 0.Therefore, after the plug process was finished, power stage circuit 401 was worked hardly.
Fig. 5 is the electrical block diagram for generation of the reference signal generator of the first reference signal Vref1 according to the utility model one embodiment.As shown in Figure 5, reference signal generator comprises linear signal generator 50, and described linear signal generator has output, and described output produces the first reference signal Vref1 with linear gradient.Described linear signal generator 50 comprises: the second current source I2 provides charging current; And second capacitor C 2, receive charging current; The wherein said first reference signal Vref1 is the voltage signal at second capacitor C, 2 two ends.
In one embodiment, output voltage VO UT has waveform shown in Figure 6, that is: at a time before the t1, output voltage VO UT is linear to rise, shown in linear signal Vlin; After moment t1, output voltage VO UT has the exponential function waveform, shown in exponential signal Vexp.
Fig. 7 is the electrical block diagram according to the reference signal generator 70 of the utility model one embodiment.The first reference signal Vref1 that described reference signal generator 70 produces has waveform shown in Figure 6.Described reference signal generator 70 comprises: index signal generator 701 has output, the exponential signal Vexp of described output output index function waveform; Linear signal generator 50 has output, and described output output device has the linear signal Vlin of linear gradient; And selection circuit 702, have first input end, second input and output, the output that described first input end is coupled to index signal generator 701 receives exponential signal Vexp, the output that described second input is coupled to linear signal generator 50 receives linear signal Vlin, described selection circuit 702 at the smaller value of output output index signal Vexp and linear signal Vlin as the first reference signal Vref1.
In one embodiment, described index signal generator 701 comprises: voltage source V 1 and resistance R e are coupled in series between the output and ground of index signal generator 701; And the 3rd capacitor C 3, with voltage source V 1 and resistance R e coupled in parallel.In one embodiment, the voltage that provides of voltage source V 1 is relevant with the value of output voltage VO UT.Those of ordinary skills should be understood that the waveform of the first reference signal Vref1 of reference signal generator 70 outputs can change by the capacitance of regulating the 3rd capacitor C 3, the magnitude of voltage of voltage source V 1 output, the resistance of resistance R e, the charging current value of second current source I2 output and the capacitance of second capacitor C 2.
When the dc-dc converter 400 that comprises reference signal generator 70 was used for hot plug, the course of work of dc-dc converter 400 is as follows: when equipment was inserted in the power-supply system, dc-dc converter 400 was started working.At this moment, the second current source I2 gives second capacitor C 2 chargings, and the voltage linear on second capacitor C 2 rises.Simultaneously, voltage source V 1 gives the 3rd capacitor C 3 chargings via resistance R e, makes voltage on the 3rd capacitor C 3 and the voltage of voltage source V 1 reach following relation:
Wherein
Characterize the slope of exponential signal Vexp.The waveform that can find out exponential signal Vexp from formula (5) is the exponential function waveform.
In the incipient stage, the value of linear signal Vlin is less than the value of exponential signal Vexp.Therefore linear signal Vlin is chosen as the first reference signal Vref1, and the waveform of output voltage VO UT is consistent with linear signal.As shown in Figure 6, from t1 constantly, the value of exponential signal Vexp is less than the value of linear signal Vlin.From t1 constantly namely, exponential signal Vexp is chosen as the first reference signal Vref1, and the waveform of output voltage VO UT is consistent with exponential signal Vexp.Between the first reference signal Vref1 rising stage, the duty ratio of dc-dc converter 400 also rises gradually.When the value of the value of output voltage VO UT and input voltage VIN was basic identical, the value slope of the first reference signal Vref1 became 0, and the duty ratio of switch converters 400 reaches 100%.Correspondingly, the electric current that flows through inductance L 1 also is 0.
Though described the utility model with reference to several exemplary embodiments, should be appreciated that used term is explanation and exemplary and nonrestrictive term.The spirit or the essence that do not break away from utility model because the utility model can specifically be implemented in a variety of forms, so be to be understood that, above-described embodiment is not limited to any aforesaid details, and should be in the spirit and scope that the claim of enclosing limits explain widely, therefore fall into whole variations in claim or its equivalent scope and remodeling and all should be the claim of enclosing and contain.
Claims (8)
1. a dc-dc converter is characterized in that, comprising:
Power stage circuit comprises power switch, and described power stage circuit has input and output, and described input receives input voltage, and described output provides output voltage;
Current detection circuit has input and output, and described input is coupled to power stage circuit, and described output provides the current detection signal that characterizes the electric current that flows through power switch;
Error amplifier has first input end, second input and output, and described first input end receives the feedback signal that characterizes output voltage, and described second input receives first reference signal, described output output compensating signal;
The pulse width modulation (PWM) comparator, have first input end, second input and output, described first input end is coupled to current detection circuit received current detection signal, and described second input is coupled to error amplifier and receives compensating signal, described output output pwm signal;
Turn-off the duration controller, have first input end, second input and input, wherein said first input end receives input voltage, and described second input receives output voltage, and the duration control signal is turn-offed in described output output; And
Logical circuit, have first input end, second input and output, the output that wherein said first input end is coupled to the PWM controller receives pwm signal, described second input is coupled to the output that turn-offs the duration controller and receives shutoff duration control signal, and described output output switch control signal is controlled the break-make of power switch.
2. dc-dc converter as claimed in claim 1 is characterized in that, also comprises:
Current foldback circuit, have first input end, second input and output, wherein said first input end is coupled to current detection circuit received current detection signal, and described second input receives peak-current signal, described output output overcurrent guard signal;
Wherein, described logical circuit also has the 3rd input, and the output that described the 3rd input is coupled to current foldback circuit receives the overcurrent protection signal, and described output output switch control signal is controlled the break-make of power switch.
3. as claim 1 or 2 each described dc-dc converters, it is characterized in that described shutoff duration controller comprises:
First current source provides the charging current that is directly proportional with input voltage;
First electric capacity has first end and second end, and described first end is coupled to first current source and receives charging current, the described second end ground connection;
First switch has first end, second end and control end, and described first end is coupled to first current source, the described second end ground connection, and described control end is coupled to the output receiving key control signal of logical circuit; And
Turn-off duration control comparator, have first input end, second input and output, first termination that wherein said first input end is coupled to first electric capacity is received the voltage on the electric capacity on the, second reference signal that the described second input reception is directly proportional with the difference of input voltage and output voltage, described shutoff duration control comparator turn-offs the duration control signal in output output.
4. dc-dc converter as claimed in claim 3 is characterized in that, also comprises reference signal generator, and described reference signal generator produces first reference signal, comprising:
Index signal generator has output, and described output output has the exponential signal of exponential function waveform;
The linear signal generator has output, and described output output device has the linear signal of linear gradient; And
Select circuit, have first input end, second input and output, the output that described first input end is coupled to index signal generator receives exponential signal, the output that described second input is coupled to the linear signal generator receives linear signal, described selection circuit at the smaller value of output output index signal and linear signal as first reference signal.
5. a dc-dc converter is characterized in that, comprising:
Power stage circuit comprises power switch, and described power stage circuit has input and output, and described input receives input voltage, and described output provides output voltage;
Current detection circuit has input and output, and described input is coupled to power stage circuit, and described output provides the current detection signal that characterizes the electric current that flows through power switch;
The PWM controller has first input end, second input and output, and wherein said first input end receives the feedback signal of the output voltage that characterizes dc-dc converter, the described second input received current detection signal, described output output pwm signal;
Turn-off the duration controller, have first input end, second input and input, the input voltage of wherein said first input end receiving key transducer, the output voltage of the described second input receiving key transducer, the duration control signal is turn-offed in described output output; And
Logical circuit, have first input end, second input and output, the output that wherein said first input end is coupled to the PWM controller receives pwm signal, described second input is coupled to the output that turn-offs the duration controller and receives shutoff duration control signal, and described output output switch control signal is controlled the break-make of power switch.
6. dc-dc converter as claimed in claim 5, it is characterized in that, also comprise current foldback circuit, have first input end, second input and output, wherein said first input end is coupled to current detection circuit received current detection signal, described second input receives peak-current signal, described output output overcurrent guard signal;
Wherein, described logical circuit also has the 3rd input, and the output that described the 3rd input is coupled to current foldback circuit receives the overcurrent protection signal, and described output output switch control signal is controlled the break-make of power switch.
7. as claim 5 or 6 each described dc-dc converters, it is characterized in that described shutoff duration controller comprises:
First current source provides the charging current that is directly proportional with input voltage;
First electric capacity has first end and second end, and described first end is coupled to first current source and receives charging current, the described second end ground connection;
First switch has first end, second end and control end, and described first end is coupled to first current source, the described second end ground connection, and described control end is coupled to the output receiving key control signal of logical circuit; And
Turn-off duration control comparator, have first input end, second input and output, first termination that wherein said first input end is coupled to first electric capacity is received the voltage on first electric capacity, second reference signal that the described second input reception is directly proportional with the difference of input voltage and output voltage, described shutoff duration control comparator turn-offs the duration control signal in output output.
8. dc-dc converter as claimed in claim 7 is characterized in that, also comprises reference signal generator, and described reference signal generator produces first reference signal, comprising:
Index signal generator has output, and described output output has the exponential signal of exponential function waveform;
The linear signal generator has output, and described output output device has the linear signal of linear gradient; And
Select circuit, have first input end, second input and output, the output that described first input end is coupled to index signal generator receives exponential signal, the output that described second input is coupled to the linear signal generator receives linear signal, described selection circuit at the smaller value of output output index signal and linear signal as first reference signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320109062 CN203206119U (en) | 2013-03-11 | 2013-03-11 | Switching converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320109062 CN203206119U (en) | 2013-03-11 | 2013-03-11 | Switching converter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203206119U true CN203206119U (en) | 2013-09-18 |
Family
ID=49150178
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201320109062 Expired - Fee Related CN203206119U (en) | 2013-03-11 | 2013-03-11 | Switching converter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203206119U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103151925A (en) * | 2013-03-11 | 2013-06-12 | 成都芯源系统有限公司 | Switch converter and control method thereof |
| CN110752586A (en) * | 2019-08-01 | 2020-02-04 | 成都芯源系统有限公司 | Switching power supply and driving current and driving method thereof |
| WO2021226978A1 (en) * | 2020-05-15 | 2021-11-18 | 深圳市汇顶科技股份有限公司 | Power supply management circuit, chip, and device |
-
2013
- 2013-03-11 CN CN 201320109062 patent/CN203206119U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103151925A (en) * | 2013-03-11 | 2013-06-12 | 成都芯源系统有限公司 | Switch converter and control method thereof |
| CN103151925B (en) * | 2013-03-11 | 2015-08-19 | 成都芯源系统有限公司 | A kind of dc-dc converter and control method thereof |
| CN110752586A (en) * | 2019-08-01 | 2020-02-04 | 成都芯源系统有限公司 | Switching power supply and driving current and driving method thereof |
| CN110752586B (en) * | 2019-08-01 | 2022-02-18 | 成都芯源系统有限公司 | Switching power supply and driving current and driving method thereof |
| WO2021226978A1 (en) * | 2020-05-15 | 2021-11-18 | 深圳市汇顶科技股份有限公司 | Power supply management circuit, chip, and device |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103151925B (en) | A kind of dc-dc converter and control method thereof | |
| CN103683908B (en) | Switching power source control circuit, Switching Power Supply and control method thereof | |
| CN101295922B (en) | Soft starting device capable of implementing linear control | |
| CN107959421B (en) | BUCK-BOOST type direct current converter and control method thereof | |
| CN105356750A (en) | Switching mode power supply equipped with overvoltage protection circuit, controller, and overvoltage protection method | |
| CN103887984A (en) | Isolating converter and switching power supply comprising same | |
| CN203607871U (en) | Battery discharging circuit and controller therefor | |
| CN103095135A (en) | Switch convertor and slope compensating circuit thereof | |
| CN102801305A (en) | Peak current signal generating circuit, switching power supply circuit and method for generating peak current signals | |
| CN102611306A (en) | Switch converter, control circuit of switch converter and control method of switch converter | |
| CN101552570A (en) | A switch voltage regulation circuit and method with a frequency limiting function | |
| CN103208934A (en) | Pulse width modulation switching power supply controller and switching power supply | |
| CN201230276Y (en) | Synchronous peak value current control mode impulse-width modulation DC/DC converter | |
| CN105356746A (en) | Conduction time generation circuit for power supply converter, and power supply converter | |
| CN103066823A (en) | Controller and control method of switch power source | |
| CN202475254U (en) | Switching converter and control circuit thereof | |
| CN104779792A (en) | Control circuit and control method of vehicle-mounted charger DC-DC system | |
| CN203206119U (en) | Switching converter | |
| CN203135724U (en) | Switching converter and slope compensation circuit thereof | |
| CN104283420A (en) | Voltage conversion controller with voltage drop compensation function and voltage conversion circuit | |
| CN203466720U (en) | Circuit reducing opening time in current control type switching regulating system | |
| CN103414323A (en) | Circuit for reducing turn-on time of current control type switch adjusting system | |
| CN201846229U (en) | Soft start circuit | |
| CN202713146U (en) | Peak current signal generating circuit and switching power supply circuit | |
| CN114649936A (en) | Switch converter and control circuit thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130918 Termination date: 20170311 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |