Transient response control circuit and voltage converter

Abstract

The present application is applicable to the technical field of voltage converters, and provides a transient response control circuit and a voltage converter. The transient response control circuit includes a first comparison module, a second comparison module, a logic module and a voltage regulation module, the first comparison module is electrically connected to the second comparison module, the logic module and the voltage regulation module respectively, the second comparison module is electrically connected to the voltage regulation module, the first comparison module, the second comparison module and the voltage regulation module are all used to be electrically connected to the loop compensation circuit, and the logic module is used to be electrically connected to the signal generation circuit and the trigger circuit respectively. When the load suddenly changes and causes the output voltage to change, the embodiment of the present application can realize rapid regulation of the output voltage by adding a transient response control circuit, so that the output voltage can be quickly restored to the set value. The problem that the output voltage of the existing voltage converter has a large change amplitude and a slow transient response speed when the load suddenly changes is solved, and the transient response speed of the voltage converter is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of voltage converters, and in particular relates to a transient response control circuit and a voltage converter. Background Art

[0002] Transient response refers to the voltage converter's ability to react quickly to a sudden load change, providing enough power in a short period of time to make the output stable without large overshoot or undershoot. However, for voltage converters, especially boost converters, due to the existence of right half plane zeros, their loop bandwidth is subject to certain limitations, and their load transient response characteristics cannot be improved by increasing the loop bandwidth, resulting in a slow load transient response speed of the voltage converter. Summary of the invention

[0003] The embodiments of the present application provide a transient response control circuit and a voltage converter, which can solve the problem of slow load transient response speed of the existing voltage converter.

[0004] In a first aspect, an embodiment of the present application provides a transient response control circuit, comprising a first comparison module, a second comparison module, a logic module and a voltage regulation module, wherein the first comparison module is electrically connected to the second comparison module, the logic module and the voltage regulation module respectively, the second comparison module is electrically connected to the voltage regulation module, the first comparison module, the second comparison module and the voltage regulation module are all used to be electrically connected to a loop compensation circuit in a voltage converter, and the logic module is used to be electrically connected to a signal generating circuit in the voltage converter and a trigger circuit in the voltage converter respectively;

[0005] When the output voltage of the voltage converter increases to a first preset value, the first comparison module is used to output a first comparison signal, and the logic module is used to output a first logic signal according to the first comparison signal and the clock signal output by the signal generating circuit, wherein the first logic signal is used to indicate that the output voltage of the voltage converter decreases;

[0006] When the output voltage of the voltage converter decreases to a second preset value, the second comparison module is used to output a second comparison signal, and the voltage regulation module is used to increase the node voltage according to the second comparison signal to increase the output voltage of the voltage converter, wherein the node voltage is the voltage of the common end of the voltage regulation module and the loop compensation circuit.

[0007] In a possible implementation of the first aspect, the first comparison module includes a first comparator, a first input end of the first comparator is electrically connected to the second comparison module and the first end of the compensation resistor in the loop compensation circuit, respectively, a second input end of the first comparator is electrically connected to the second comparison module, the second end of the compensation resistor, the voltage regulation module and the first end of the compensation capacitor in the loop compensation circuit, respectively, and an output end of the first comparator is electrically connected to the logic module.

[0008] In a possible implementation of the first aspect, the second comparison module includes a second comparator, a first input end of the second comparator is electrically connected to the first comparison module and the first end of the compensation resistor in the loop compensation circuit, respectively, a second input end of the second comparator is electrically connected to the first comparison module, the second end of the compensation resistor, the voltage regulation module and the first end of the compensation capacitor in the loop compensation circuit, respectively, and an output end of the second comparator is electrically connected to the voltage regulation module.

[0009] In a possible implementation of the first aspect, the logic module includes an NOR gate, a first input end of the NOR gate is electrically connected to the first comparison module, a second input end of the NOR gate is used to be electrically connected to the signal generating circuit, and an output end of the NOR gate is used to be electrically connected to the trigger circuit.

[0010] In a possible implementation manner of the first aspect, the voltage regulating module includes a first switch unit, a voltage generating unit, and a current output unit, the first switch unit is electrically connected to the first comparison module, the second comparison module, the loop compensation circuit, and the voltage generating unit, respectively, and the voltage generating unit is electrically connected to the current output unit;

[0011] The current output unit is used to output a first current, the voltage generating unit is used to output a first voltage to the first switch unit according to the first current, and the first switch unit is used to be turned on according to the second comparison signal and transmit the first voltage to the loop compensation circuit.

[0012] In a possible implementation of the first aspect, the first switching unit includes a first switching tube, a gate of the first switching tube is electrically connected to the second comparison module, a source of the first switching tube is used to be electrically connected to the loop compensation circuit, and a drain of the first switching tube is electrically connected to the voltage generating unit.

[0013] In a possible implementation of the first aspect, the voltage generating unit includes a first resistor, a second switch tube and a third switch tube, the first end of the first resistor is electrically connected to the source of the third switch tube, the second end of the first resistor is grounded, the gate of the second switch tube is electrically connected to the gate of the third switch tube, the drain of the third switch tube and the current output unit respectively, the source of the second switch tube is electrically connected to the first switch unit, and the drain of the second switch tube is used to be electrically connected to the first power supply.

[0014] In a possible implementation manner of the first aspect, the current output unit includes a first current source, a first end of the first current source is used to be electrically connected to a first power supply, and a second end of the first current source is electrically connected to the voltage generating unit.

[0015] In a possible implementation manner of the first aspect, the current output unit includes a second resistor, a fourth switch tube, a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube, the first end of the second resistor is used to receive the output voltage of the voltage converter, the second end of the second resistor is electrically connected to the source of the fourth switch tube, the gate of the fourth switch tube is used to receive the input voltage of the voltage converter, the drain of the fourth switch tube is electrically connected to the drain of the fifth switch tube, the gate of the fifth switch tube and the gate of the sixth switch tube respectively, the drain of the sixth switch tube is electrically connected to the drain of the seventh switch tube, the gate of the seventh switch tube and the gate of the eighth switch tube respectively, the source of the sixth switch tube and the source of the fifth switch tube are both grounded, the source of the eighth switch tube and the source of the seventh switch tube are both used to receive the input voltage of the voltage converter, and the drain of the eighth switch tube is electrically connected to the voltage generating unit.

[0016] In a second aspect, an embodiment of the present application provides a voltage converter, comprising the transient response control circuit described in any one of the first aspects.

[0017] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0018] The transient response control circuit provided by the embodiment of the present application includes a first comparison module, a second comparison module, a logic module and a voltage regulation module. The first comparison module and the logic module are used for response control when the load changes rapidly from heavy load to light load, that is, when the load changes rapidly from heavy load to light load, the output voltage of the voltage converter begins to increase, and when the output voltage increases to a first preset value, the first comparison module outputs a first comparison signal, and the logic module outputs a first logic signal according to the first comparison signal and the clock signal. The trigger circuit in the voltage converter is used to receive the first logic signal and the first reset signal, and output the first trigger signal. The drive circuit in the voltage converter outputs corresponding drive signals to the lower power tube and the upper power tube in the voltage conversion circuit according to the first trigger signal, so that the lower power tube is no longer turned on in the next cycle, the inductor current in the voltage conversion circuit drops rapidly to zero, the output voltage no longer continues to increase, and drops rapidly to the set value, thereby realizing rapid regulation of the output voltage when the load changes rapidly from heavy load to light load. The second comparison module and the voltage regulation module are used for response control when the load changes rapidly from light load to heavy load, that is, when the load changes rapidly from light load to heavy load, the output voltage of the voltage converter begins to decrease. When the output voltage decreases to the second preset value, the second comparison module outputs a second comparison signal, and the voltage regulation module rapidly increases the node voltage according to the second comparison signal, thereby rapidly increasing the reference voltage output by the operational amplifier circuit in the voltage converter. The comparison circuit in the voltage converter outputs a second reset signal according to the reference voltage and the sawtooth wave signal output by the signal generating circuit. The trigger circuit outputs a second trigger signal according to the second reset signal. The drive circuit outputs a corresponding drive signal to the lower power tube and the upper power tube according to the second trigger signal to increase the duty cycle of the voltage conversion circuit, so that the inductor current increases rapidly, the output voltage no longer continues to decrease, and rapidly rises to the set value, thereby realizing rapid regulation of the output voltage when the load changes rapidly from light load to heavy load.

[0019] As can be seen from the above, when the load suddenly changes and causes the output voltage to change, the embodiment of the present application can achieve rapid regulation of the output voltage by adding a transient response control circuit in the voltage converter, so that the output voltage can be quickly restored to the set value. The problem of the existing voltage converter having a large change amplitude of the output voltage and slow transient response speed when the load suddenly changes is solved, and the transient response speed of the voltage converter is improved.

[0020] It can be understood that the beneficial effects of the second aspect mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 is a principle block diagram of a transient response control circuit provided in an embodiment of the present application;

[0023] Figure 2 is a circuit connection diagram of a transient response control circuit provided in an embodiment of the present application;

[0024] Figure 3 This is a schematic diagram of a circuit connection of a first comparator and a second comparator provided in an embodiment of the present application;

[0025] Figure 4 This is another circuit connection diagram of a current output unit provided in an embodiment of the present application;

[0026] Figure 5 It is a schematic diagram of the working waveform of the voltage converter provided in one embodiment of the present application.

[0027] In the figure, 10, transient response control circuit; 101, first comparison module; 102, second comparison module; 103, logic module; 104, voltage regulation module; 1041, first switch unit; 1042, voltage generating unit; 1043, current output unit; 20, loop compensation circuit; 30, signal generating circuit; 40, trigger circuit; 50, drive circuit; 60, voltage conversion circuit; 70, voltage divider circuit; 80, operational amplifier circuit; 90, comparison circuit. DETAILED DESCRIPTION

[0028] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0029] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0030] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0031] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0032] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0033] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0034] For voltage converters, especially boost converters, due to the existence of right half plane zeros, their loop bandwidth is subject to certain limitations, and their load transient response characteristics cannot be improved by increasing the loop bandwidth, resulting in slow load transient response speed of the voltage converter.

[0035] Based on the above problems, the transient response control circuit provided by the embodiment of the present application includes a first comparison module, a second comparison module, a logic module and a voltage regulation module. The first comparison module and the logic module are used for response control when the load changes rapidly from heavy load to light load, that is, when the load changes rapidly from heavy load to light load, the output voltage of the voltage converter begins to increase. When the output voltage increases to a first preset value, the first comparison module outputs a first comparison signal, and the logic module outputs a first logic signal according to the first comparison signal and the clock signal. The trigger circuit in the voltage converter is used to receive the first logic signal and the first reset signal, and output the first trigger signal. The drive circuit in the voltage converter outputs corresponding drive signals to the lower power tube and the upper power tube in the voltage conversion circuit according to the first trigger signal, so that the lower power tube is no longer turned on in the next cycle, the inductor current in the voltage conversion circuit drops rapidly to zero, the output voltage no longer continues to increase, and drops rapidly to the set value, thereby realizing rapid regulation of the output voltage when the load changes rapidly from heavy load to light load. The second comparison module and the voltage regulation module are used for response control when the load changes rapidly from light load to heavy load, that is, when the load changes rapidly from light load to heavy load, the output voltage of the voltage converter begins to decrease. When the output voltage decreases to the second preset value, the second comparison module outputs a second comparison signal, and the voltage regulation module rapidly increases the node voltage according to the second comparison signal, thereby rapidly increasing the reference voltage output by the operational amplifier circuit in the voltage converter. The comparison circuit in the voltage converter outputs a second reset signal according to the reference voltage and the sawtooth wave signal output by the signal generating circuit. The trigger circuit outputs a second trigger signal according to the second reset signal. The drive circuit outputs a corresponding drive signal to the lower power tube and the upper power tube according to the second trigger signal to increase the duty cycle of the voltage conversion circuit, so that the inductor current increases rapidly, the output voltage no longer continues to decrease, and rapidly rises to the set value, thereby realizing rapid regulation of the output voltage when the load changes rapidly from light load to heavy load.

[0036] As can be seen from the above, when the load suddenly changes and causes the output voltage to change, the embodiment of the present application can achieve rapid regulation of the output voltage by adding a transient response control circuit in the voltage converter, so that the output voltage can be quickly restored to the set value. The problem of the existing voltage converter having a large change amplitude of the output voltage and slow transient response speed when the load suddenly changes is solved, and the transient response speed of the voltage converter is improved.

[0037] In order to illustrate the technical solution described in this application, a specific embodiment is provided below for illustration.

[0038] Figure 1 FIG. 1 shows a schematic block diagram of a transient response control circuit 10 provided in an embodiment of the present application. Figure 1As shown, the transient response control circuit 10 includes a first comparison module 101, a second comparison module 102, a logic module 103 and a voltage regulation module 104. The first comparison module 101 is electrically connected to the second comparison module 102, the logic module 103 and the voltage regulation module 104 respectively, the second comparison module 102 is electrically connected to the voltage regulation module 104, the first comparison module 101, the second comparison module 102 and the voltage regulation module 104 are all used to be electrically connected to the loop compensation circuit 20 in the voltage converter, and the logic module 103 is used to be electrically connected to the signal generating circuit 30 in the voltage converter and the trigger circuit 40 in the voltage converter respectively.

[0039] Specifically, the first comparison module 101 and the logic module 103 are used for response control when the load changes rapidly from heavy load to light load, that is, when the load changes rapidly from heavy load to light load, the output voltage VOUT of the voltage converter begins to increase, and when the output voltage VOUT increases to a first preset value, the first comparison module 101 outputs a first comparison signal, and the logic module 103 outputs a first logic signal according to the first comparison signal and the clock signal. The trigger circuit 40 in the voltage converter is used to receive the first logic signal and the first reset signal, and output the first trigger signal. The drive circuit 50 in the voltage converter outputs a corresponding drive signal to the lower power tube N1 and the upper power tube P1 in the voltage conversion circuit 60 according to the first trigger signal, so that the lower power tube N1 is no longer turned on in the next cycle, the current of the inductor L in the voltage conversion circuit 60 drops rapidly to zero, and the output voltage VOUT no longer continues to increase, and drops rapidly to the set value, thereby realizing the rapid regulation of the output voltage VOUT when the load changes rapidly from heavy load to light load. The second comparison module 102 and the voltage regulation module 104 are used for response control when the load changes rapidly from a light load to a heavy load, that is, when the load changes rapidly from a light load to a heavy load, the output voltage VOUT of the voltage converter begins to decrease. When the output voltage VOUT decreases to a second preset value, the second comparison module 102 outputs a second comparison signal, and the voltage regulation module 104 rapidly increases the node voltage according to the second comparison signal, thereby rapidly increasing the reference voltage VCOMP output by the operational amplifier circuit 80 in the voltage converter. The comparison circuit 90 in the voltage converter outputs a second reset signal according to the reference voltage VCOMP and the sawtooth wave signal output by the signal generating circuit 30. The trigger circuit 40 outputs a second trigger signal according to the second reset signal. The drive circuit 50 outputs a corresponding drive signal to the lower power tube N1 and the upper power tube P1 according to the second trigger signal to increase the duty cycle of the voltage conversion circuit 60, so that the current of the inductor L increases rapidly, and the output voltage VOUT no longer continues to decrease, and rapidly rises to the set value, thereby realizing rapid regulation of the output voltage VOUT when the load changes rapidly from a light load to a heavy load.

[0040] As can be seen from the above, when the load suddenly changes and causes the output voltage VOUT to change, the embodiment of the present application can quickly adjust the output voltage VOUT by adding a transient response control circuit 10 in the voltage converter, so that the output voltage VOUT quickly returns to the set value. The problem of the existing voltage converter having a large change amplitude of the output voltage VOUT and a slow transient response speed when the load suddenly changes is solved, and the transient response speed of the voltage converter is improved.

[0041] It should be noted that the first change amplitude (overshoot amplitude) when the output voltage VOUT increases to the first preset value can be set equal to the second change amplitude (undershoot amplitude) when the output voltage VOUT decreases to the second preset value, or the first change amplitude and the second change amplitude can be set to be unequal, and can be adjusted according to the specific offset of the first comparison module 101 and the second comparison module 102. In the embodiment of the present application, by adding a transient response control circuit 10, when the amplitude of the rapid decrease or rapid increase of the output voltage VOUT reaches a certain value, the transient response control circuit 10 can intervene in the control to achieve rapid adjustment of the output voltage VOUT, so that the output voltage VOUT is less affected by the load change.

[0042] It should be noted that the voltage converter mainly includes a loop compensation circuit 20, a voltage divider circuit 70, an operational amplifier circuit 80, a comparison circuit 90, a trigger circuit 40, a signal generating circuit 30, a driving circuit 50, a voltage conversion circuit 60 and the above-mentioned transient response control circuit 10. The loop compensation circuit 20 is electrically connected to the operational amplifier circuit 80, the comparison circuit 90, the first comparison module 101, the second comparison module 102 and the voltage regulating module 104 in the transient response control circuit 10, respectively; the trigger circuit 40 is electrically connected to the driving circuit 50, the comparison circuit 90 and the logic module 103 in the transient response control circuit 10, respectively; the voltage conversion circuit 60 is electrically connected to the driving circuit 50 and the voltage divider circuit 70, respectively; the operational amplifier circuit 80 is electrically connected to the voltage divider circuit 70, and the signal generating circuit 30 is electrically connected to the comparison circuit 90 and the logic module 103, respectively.

[0043] Specifically, the voltage conversion circuit 60 is used to provide an output voltage VOUT according to a driving signal; the voltage divider circuit 70 is used to divide the output voltage VOUT and output a feedback voltage VFB to the operational amplifier circuit 80; the operational amplifier circuit 80 is used to output a reference voltage VCOMP according to the feedback voltage VFB and the reference voltage VREF; the comparison circuit 90 is used to output a reset signal (a first reset signal and a second reset signal) according to the reference voltage VCOMP and the sawtooth wave signal output by the oscillator; the trigger circuit 40 is used to output a trigger signal (a first trigger signal and a second trigger signal) according to the reset signal and the first logic signal; the driving circuit 50 outputs a corresponding driving signal to the lower power tube N1 and the upper power tube P1 according to the trigger signal; the loop compensation circuit 20 is used to form a proportional integral compensation zero point to stabilize the loop; the first comparison module 101 is used to output a first comparison signal when the output voltage VOUT of the voltage converter increases to a first preset value, and the logic module 103 is used to output a first logic signal according to the first comparison signal and the clock signal output by the signal generating circuit 30. The second comparison module 102 is used for outputting a second comparison signal when the output voltage VOUT of the voltage converter decreases to a second preset value, and the voltage regulation module 104 is used for increasing the node voltage according to the second comparison signal.

[0044] It should be noted that if Figure 2As shown, the voltage conversion circuit 60 includes an inductor L, an upper power tube P1, a lower power tube N1 and a capacitor C0. The first end of the inductor L is used to receive the input voltage VIN, and the second end of the inductor L is electrically connected to the source of the upper power tube P1 and the drain of the lower power tube N1 respectively. The gate of the upper power tube P1 and the gate of the lower power tube N1 are both electrically connected to the driving circuit 50 for receiving the driving signal output by the driving circuit 50. The drain of the upper power tube P1 is electrically connected to the first end of the capacitor C0 and the voltage divider circuit 70 respectively for providing the output voltage VOUT. The second end of the capacitor C0 and the source of the lower power tube N1 are both grounded. The voltage divider circuit 70 includes a first voltage divider resistor R10 and a second voltage divider resistor R20, wherein the first end of the first voltage divider resistor R10 is used to receive the output voltage VOUT, the second end of the first voltage divider resistor R10 is electrically connected to the first end of the second voltage divider resistor R20 and the operational amplifier circuit 80 respectively, the second end of the second voltage divider resistor R20 is grounded, the first voltage divider resistor R10 and the second voltage divider resistor R20 are used to divide the output voltage VOUT and output the feedback voltage VFB to the operational amplifier circuit 80. The operational amplifier circuit 80 includes an operational amplifier EA, wherein the first input end (negative input end) of the operational amplifier EA is used to receive the feedback voltage VFB, the second input end (positive input end) of the operational amplifier EA is used to receive the reference voltage VREF, and the output end of the operational amplifier EA is used to output the reference voltage VCOMP to the comparison circuit 90 and the loop compensation circuit 20. The comparison circuit 90 includes a PWM comparator, wherein the first input terminal (positive input terminal) of the PWM comparator is used to receive the sawtooth wave signal output by the oscillator, the second input terminal (negative input terminal) of the PWM comparator is used to receive the reference voltage VCOMP, and the output terminal of the PWM comparator is used to output a reset signal to the trigger circuit 40. The loop compensation circuit 20 includes a compensation resistor R30 and a compensation capacitor C10, wherein the first end of the compensation resistor R30 is electrically connected to the output terminal of the operational amplifier EA and the second input terminal of the PWM comparator, respectively, the second end of the compensation resistor R30 is electrically connected to the first end of the compensation capacitor C10, and the second end of the compensation capacitor C10 is grounded. The first comparison module 101 is connected in parallel to the two ends of the compensation resistor R30, and is used to output a first comparison signal according to the voltage drop of the compensation resistor R30, and the second comparison module 102 is connected in parallel to the two ends of the compensation resistor R30, and is used to output a second comparison signal according to the voltage drop of the compensation resistor R30. The voltage regulation module 104 is electrically connected to the first end of the compensation capacitor C10, and is used to increase the voltage (node ​​voltage) of the first end of the compensation capacitor C10 according to the second comparison signal. The signal generating circuit 30 includes an oscillator for outputting a sawtooth wave signal to the PWM comparator and a clock signal to the logic module 103 .The trigger circuit 40 includes an RS trigger, the R end of the RS trigger is electrically connected to the output end of the PWM comparator for receiving a reset signal, the S end of the RS trigger is electrically connected to the logic module 103 for receiving a first logic signal, and the output end (Q end) of the RS trigger is electrically connected to the drive circuit 50 for outputting a trigger signal to the drive circuit 50.

[0045] When a sudden change occurs in the load (wherein a sudden change in the load includes a sudden change from a light load to a heavy load and a sudden change from a heavy load to a light load), the first comparison module 101 / the second comparison module 102 outputs a first comparison signal / a second comparison signal, and the logic module 103 outputs a first logic signal according to the first comparison signal and the clock signal, or the voltage regulation module 104 increases the node voltage according to the second comparison signal, thereby quickly regulating the output voltage VOUT, so that the output voltage VOUT quickly returns to the set value, and improves the transient response speed of the voltage converter.

[0046] In one embodiment of the present application, Figure 2 As shown, the first comparison module 101 includes a first comparator CMP1, a first input end of the first comparator CMP1 is electrically connected to the second comparison module 102 and a first end of the compensation resistor R30 in the loop compensation circuit 20, respectively, a second input end of the first comparator CMP1 is electrically connected to the second comparison module 102, the second end of the compensation resistor R30, the voltage regulation module 104 and a first end of the compensation capacitor C10 in the loop compensation circuit 20, respectively, and an output end of the first comparator CMP1 is electrically connected to the logic module 103.

[0047] Specifically, the negative input terminal of the first comparator CMP1 serves as the first input terminal of the first comparator CMP1, and the positive input terminal of the first comparator CMP1 serves as the second input terminal of the first comparator CMP1. Since there is an offset between the two input terminals of the first comparator CMP1, that is, there is a first offset voltage, and the two input terminals of the first comparator CMP1 are connected in parallel with the compensation resistor R30. Therefore, if the voltage drop of the compensation resistor R30 is greater than the first offset voltage of the first comparator CMP1, the first comparator CMP1 outputs a first comparison signal, and the first comparison signal is a high level signal.

[0048] It should be noted that when the load changes from heavy load to light load, the output voltage VOUT will increase, thereby increasing the feedback voltage VFB transmitted to the negative input terminal of the operational amplifier EA. When the feedback voltage VFB is greater than the reference voltage VREF, a current of gm*(VFB-VREF) flows from the compensation capacitor C10 through the compensation resistor R30 to the output terminal of the operational amplifier EA. At this time, the voltage across the compensation resistor R30 is -gm*(VFB-VREF)*R30. When the voltage is greater than the first offset voltage, the first comparator CMP1 outputs a high-level signal. When the load does not change suddenly, the voltage across the compensation resistor R30 does not reach the first offset voltage, and the first comparator CMP1 cannot output a high-level signal.

[0049] In one embodiment of the present application, Figure 2 As shown, the second comparison module 102 includes a second comparator CMP2, a first input end of the second comparator CMP2 is electrically connected to the first comparison module 101 and a first end of the compensation resistor R30 in the loop compensation circuit 20, respectively, a second input end of the second comparator CMP2 is electrically connected to the first comparison module 101, a second end of the compensation resistor R30, a voltage regulation module 104 and a first end of the compensation capacitor C10 in the loop compensation circuit 20, respectively, and an output end of the second comparator CMP2 is electrically connected to the voltage regulation module 104.

[0050] Specifically, the positive input terminal of the second comparator CMP2 serves as the first input terminal of the second comparator CMP2, and the negative input terminal of the second comparator CMP2 serves as the second input terminal of the second comparator CMP2. Since there is an offset between the two input terminals of the second comparator CMP2, that is, there is a second offset voltage, and the two input terminals of the second comparator CMP2 are connected in parallel with the compensation resistor R30. Therefore, if the voltage drop of the compensation resistor R30 is greater than the second offset voltage of the second comparator CMP2, the second comparator CMP2 outputs a second comparison signal, and the second comparison signal is a high level signal.

[0051] It should be noted that when the load changes from a light load to a heavy load, the output voltage VOUT will be reduced, thereby reducing the feedback voltage VFB transmitted to the negative input terminal of the operational amplifier EA. When the feedback voltage VFB is less than the reference voltage VREF, a current of gm*(VREF-VFB) flows to the compensation resistor R30 and charges the compensation capacitor C10. At this time, the voltage across the compensation resistor R30 is gm*(VREF-VFB)*R30. When the voltage is greater than the second offset voltage, the second comparator CMP2 outputs a high level signal. When the load does not change suddenly, the voltage across the compensation resistor R30 does not reach the second offset voltage, and the second comparator CMP2 cannot output a high level signal.

[0052] It should be noted that Figure 3 The present invention shows an implementation circuit of the first comparator CMP1 and the second comparator CMP2, including a ninth switch tube Q9, a tenth switch tube Q10, an eleventh switch tube Q11, a twelfth switch tube Q12, a thirteenth switch tube Q13, a fourteenth switch tube Q14, a fifteenth switch tube Q15, a sixteenth switch tube Q16, a seventeenth switch tube Q17, a third resistor R3 and a buffer U1; the source of the ninth switch tube Q9, the source of the tenth switch tube Q10 and the source of the eleventh switch tube Q11 are all used to receive the input voltage VIN, the gate of the ninth switch tube Q9 is electrically connected to the drain of the ninth switch tube Q9, the gate of the tenth switch tube Q10, the drain of the tenth switch tube Q10, the drain of the fourteenth switch tube Q14, the drain of the seventeenth switch tube Q17 and the input end of the buffer U1, the gate of the eleventh switch tube Q11 is used to receive the bias voltage Vbias, and the gate of the eleventh switch tube Q11 is electrically connected to the input end of the buffer U1. The drain is electrically connected to the first end of the third resistor R3 and the source of the thirteenth switch tube Q13 respectively, the gate of the twelfth switch tube Q12 is used to receive the first input voltage VN, the drain of the twelfth switch tube Q12 is electrically connected to the gate of the fourteenth switch tube Q14, the gate of the fifteenth switch tube Q15 and the drain of the fifteenth switch tube Q15 respectively, the gate of the thirteenth switch tube Q13 is used to receive the second input voltage VP, the drain of the thirteenth switch tube Q13 is electrically connected to the gate of the sixteenth switch tube Q16, the drain of the sixteenth switch tube Q16 and the gate of the seventeenth switch tube Q17 respectively, the source of the fourteenth switch tube Q14, the source of the fifteenth switch tube Q15, the source of the sixteenth switch tube Q16 and the source of the seventeenth switch tube Q17 are all grounded, and the output end of the buffer U1 serves as the output end of the first comparator CMP1 / the second comparator CMP2, and is used to output the first comparison signal / the second comparison signal.

[0053] Specifically, the third resistor R3 introduces a fixed offset voltage (a first offset voltage and a second offset voltage), and the offset voltage value is ib*R3*1 / 2, where ib is the current flowing through the eleventh switch tube Q11.

[0054] It should be noted that the present application is not limited to the specific implementation of the above comparators (the first comparator CMP1 and the second comparator CMP2 ), and other implementations may be possible, and the offset voltage may be adjusted accordingly as needed, which is not limited here.

[0055] For example, the designer can select the types of the ninth switch tube Q9, the tenth switch tube Q10, the eleventh switch tube Q11, the twelfth switch tube Q12, the thirteenth switch tube Q13, the fourteenth switch tube Q14, the fifteenth switch tube Q15, the sixteenth switch tube Q16 and the seventeenth switch tube Q17 according to the actual situation, that is, all of them can adopt fully controlled power devices such as metal oxide field effect transistors or insulated gate bipolar transistors. For example, the ninth switch tube Q9, the tenth switch tube Q10, the eleventh switch tube Q11, the twelfth switch tube Q12 and the thirteenth switch tube Q13 can be selected as PMOS tubes, and the fifteenth switch tube Q15, the sixteenth switch tube Q16 and the seventeenth switch tube Q17 can be selected as NMOS tubes.

[0056] In one embodiment of the present application, Figure 2 As shown, the logic module 103 includes a NOR gate nor1, a first input end of the NOR gate nor1 is electrically connected to the first comparison module 101, a second input end of the NOR gate nor1 is used to be electrically connected to the signal generating circuit 30, and an output end of the NOR gate nor1 is used to be electrically connected to the trigger circuit 40.

[0057] Specifically, the first input end of the NOR gate nor1 is used to receive the first comparison signal, and the second input end of the NOR gate nor1 is used to receive the clock signal. After receiving the first comparison signal and the clock signal, the NOR gate nor1 performs an NOR operation on the first comparison signal and the clock signal, that is, the first comparison signal and the clock signal are firstly ORed, and then the result after the OR operation is NORed, and finally the corresponding logic signal is output. The specific operation logic of the NOR operation is: only when the first comparison signal and the clock signal are both low level, the output end of the NOR gate nor1 outputs a high level, otherwise, the output end of the NOR gate nor1 outputs a low level. It can be seen that when the load changes from heavy load to light load, the first comparison signal is a high level signal, and at this time, the first logic signal outputted from the output end of the NOR gate nor1 is a low level signal. After the S end of the RS trigger receives a low level signal, it indicates that the clock signal is prohibited from being input to the RS trigger, and at this time, the first trigger signal outputted from the Q end of the RS trigger is a low level signal. The drive circuit 50 outputs corresponding drive signals to the lower power tube N1 and the upper power tube P1 in the voltage conversion circuit 60 according to the first trigger signal, so that the lower power tube N1 is no longer turned on in the next cycle, the current of the inductor L in the voltage conversion circuit 60 drops rapidly to zero, and the output voltage VOUT no longer continues to increase, but drops rapidly to the set value, thereby realizing rapid regulation of the output voltage VOUT when the load changes rapidly from heavy load to light load.

[0058] In one embodiment of the present application, Figure 2As shown, the voltage regulation module 104 includes a first switch unit 1041, a voltage generating unit 1042 and a current output unit 1043. The first switch unit 1041 is electrically connected to the first comparison module 101, the second comparison module 102, the loop compensation circuit 20 and the voltage generating unit 1042 respectively, and the voltage generating unit 1042 is electrically connected to the current output unit 1043.

[0059] Specifically, the current output unit 1043 is used to output a constant first current and transmit it to the voltage generating unit 1042. After receiving the first current, the voltage generating unit 1042 determines a first voltage according to the first current, and outputs the first voltage to the first switch unit 1041. The first switch unit 1041 can be turned on according to the second comparison signal, that is, the first voltage can be transmitted to the first end of the compensation capacitor C10 in the loop compensation circuit 20, so that the voltage of the first end of the compensation capacitor C10 increases, thereby increasing the reference voltage VCOMP.

[0060] In one embodiment of the present application, Figure 2 As shown, the first switch unit 1041 includes a first switch tube Q1, the gate of the first switch tube Q1 is electrically connected to the second comparison module 102, the source of the first switch tube Q1 is used to be electrically connected to the loop compensation circuit 20, and the drain of the first switch tube Q1 is electrically connected to the voltage generating unit 1042.

[0061] Specifically, the first switch tube Q1, as a switch device, can be turned on or off according to the second comparison signal received by the gate. When the load changes from light load to heavy load, the second comparison signal output by the second comparator CMP2 is a high level signal, and the first switch tube Q1 is turned on according to the high level signal, so that the voltage at the first end of the compensation capacitor C10 can be increased.

[0062] For example, designers can select the type of the first switch tube Q1 according to actual conditions, that is, fully controlled power devices such as metal oxide field effect transistors or insulated gate bipolar transistors can be used. For example, the first switch tube Q1 can be selected as an NMOS tube.

[0063] In one embodiment of the present application, Figure 2 As shown, the voltage generating unit 1042 includes a first resistor R1, a second switch tube Q2 and a third switch tube Q3, the first end of the first resistor R1 is electrically connected to the source of the third switch tube Q3, the second end of the first resistor R1 is grounded, the gate of the second switch tube Q2 is electrically connected to the gate of the third switch tube Q3, the drain of the third switch tube Q3 and the current output unit 1043 respectively, the source of the second switch tube Q2 is electrically connected to the first switch unit 1041, and the drain of the second switch tube Q2 is used to be electrically connected to the first power supply VDD.

[0064] Specifically, the second switch tube Q2 and the third switch tube Q3 are used as a simple voltage stabilizer to generate a constant voltage with a large driving capability, and the first resistor R1 is used to convert the first current output by the current output unit 1043 into a first voltage. Specifically, when the load changes from a light load to a heavy load, the first switch tube Q1 is turned on, and the second switch tube Q2, the first switch tube Q1 and the compensation capacitor C10 are connected in series. At this time, the voltage at the first end of the compensation capacitor C10 rises rapidly to the product of the first current and the first resistor R1, that is, I0*R1. As a result, the reference voltage VCOMP changes rapidly to gm*(VREF-VFB)*R30+I0*R1, and the comparison circuit 90 outputs a second reset signal according to the reference voltage VCOMP and the sawtooth wave signal output by the signal generation circuit 30. The trigger circuit 40 outputs a second trigger signal according to the second reset signal. The drive circuit 50 outputs corresponding drive signals to the lower power tube N1 and the upper power tube P1 according to the second trigger signal to increase the duty cycle of the voltage conversion circuit 60, so that the current of the inductor L increases rapidly, and the output voltage VOUT no longer continues to decrease, and quickly rises to the set value, thereby achieving rapid regulation of the output voltage VOUT when the load changes rapidly from light load to heavy load.

[0065] For example, the designer can select the type of the second switch tube Q2 and the third switch tube Q3 according to the actual situation, that is, both can use fully controlled power devices such as metal oxide field effect transistors or insulated gate bipolar transistors. For example, the second switch tube Q2 and the third switch tube Q3 can be selected as NMOS tubes.

[0066] In one embodiment of the present application, Figure 2 As shown, the current output unit 1043 includes a first current source I0 , a first end of the first current source I0 is used to be electrically connected to the first power source VDD, and a second end of the first current source I0 is electrically connected to the voltage generating unit 1042 .

[0067] Specifically, the first current source I0 is used to generate a constant first current and transmit it to the voltage generating unit 1042, so that the voltage generating unit 1042 increases the voltage of the first end of the compensation capacitor C10 according to the first current, and finally achieves the purpose of regulating the output voltage VOUT.

[0068] Since the input voltage VIN and the output voltage VOUT of a general voltage converter (such as a boost converter) may vary greatly, in order to obtain a better transient response under different input voltages VIN and output voltages VOUT, the first current source I0 may be appropriately improved.

[0069] Specifically, in one embodiment of the present application, Figure 4As shown, the current output unit 1043 includes a second resistor R2, a fourth switch tube Q4, a fifth switch tube Q5, a sixth switch tube Q6, a seventh switch tube Q7 and an eighth switch tube Q8. The first end of the second resistor R2 is used to receive the output voltage VOUT of the voltage converter. The second end of the second resistor R2 is electrically connected to the source of the fourth switch tube Q4. The gate of the fourth switch tube Q4 is used to receive the input voltage VIN of the voltage converter. The drain of the fourth switch tube Q4 is electrically connected to the drain of the fifth switch tube Q5, the gate of the fifth switch tube Q5 and the gate of the sixth switch tube Q6 respectively. The drain of the sixth switch tube Q6 is electrically connected to the drain of the seventh switch tube Q7, the gate of the seventh switch tube Q7 and the gate of the eighth switch tube Q8 respectively. The source of the sixth switch tube Q6 and the source of the fifth switch tube Q5 are both grounded. The source of the eighth switch tube Q8 and the source of the seventh switch tube Q7 are both used to receive the input voltage VIN of the voltage converter. The drain of the eighth switch tube Q8 is electrically connected to the voltage generating unit 1042.

[0070] Specifically, the design of the current output unit 1043 can make the first current output by the current output unit 1043 approximately proportional to the difference between the output voltage VOUT and the input voltage VIN, that is, the higher the output voltage VOUT, the lower the input voltage VIN. When the load changes rapidly from a light load to a heavy load, the higher the amplitude of the rapid change of the voltage at the first end of the compensation capacitor C10, and thus the faster the current of the inductor L rises, the smaller the undershoot amplitude of the output voltage VOUT, and thus the transient response speed of the voltage converter is greatly improved.

[0071] For example, the designer can select the types of the fourth switch tube Q4, the fifth switch tube Q5, the sixth switch tube Q6, the seventh switch tube Q7 and the eighth switch tube Q8 according to the actual situation, that is, they can all adopt fully controlled power devices such as metal oxide field effect transistors or insulated gate bipolar transistors. For example, the fourth switch tube Q4, the seventh switch tube Q7 and the eighth switch tube Q8 can all be PMOS tubes, and the fifth switch tube Q5 and the sixth switch tube Q6 can all be NMOS tubes.

[0072] It should be noted that, through the above working principle analysis and calculation, it can be obtained that when the output voltage VOUT increases to the first preset value, the first change amplitude (overshoot amplitude) is [(R10+R20*vos1)] / (R20*gm*R30), the transient response control circuit 10 will intervene in the control, that is, the first comparison module 101 outputs the first comparison signal, and the logic module 103 outputs the first logic signal according to the first comparison signal and the clock signal output by the signal generating circuit 30. Among them, vos1 is the offset of the first comparator CMP1, and gm is the transconductance of the operational amplifier EA. Similarly, when the output voltage VOUT decreases to the second preset value, the second change amplitude (undershoot amplitude) is [(R10+R20*vos2)] / (R20*gm*R30), the second comparison module 102 outputs the second comparison signal, and the voltage regulating module 104 increases the node voltage according to the second comparison signal. Among them, vos2 is the offset of the second comparator CMP2.

[0073] The working waveform diagram of the voltage converter is shown in Figure 5 As shown, the horizontal axis is time t, and from top to bottom are the waveforms of the output voltage VOUT, the reference voltage VCOMP and the voltage at the first terminal of the compensation capacitor C10, and the waveform of the inductor current IL. Among them, in the first waveform diagram, the thin line is the waveform of the output voltage VOUT without the transient response control circuit 10, and the thick line is the waveform of the output voltage VOUT with the transient response control circuit 10 added in this application. In the second waveform diagram, the thin line is the waveform of the reference voltage VCOMP, and the thick line is the waveform of the voltage at the first terminal of the compensation capacitor C10. By Figure 5 It can be seen that when the load suddenly changes, the voltage at the first terminal of the compensation capacitor C10 will change accordingly, causing the voltage of the reference voltage VCOMP to change accordingly, thereby causing the inductor current IL to change, and finally achieving the regulation of the output voltage VOUT. It can be seen that the present application can achieve rapid regulation of the output voltage VOUT by adding a transient response control circuit 10 to the voltage converter, so that the output voltage VOUT can be quickly restored to the set value, thereby improving the transient response speed of the voltage converter.

[0074] The present application also discloses a voltage converter, including the above-mentioned transient response control circuit. The voltage converter adopts the above-mentioned transient response control circuit to solve the problem of large output voltage change amplitude and slow transient response speed of the existing voltage converter when the load suddenly changes, thereby improving the transient response speed of the voltage converter.

[0075] Since the processing and functions implemented by the control system and the voltage converter in this embodiment basically correspond to the embodiments, principles and examples of the aforementioned transient response control circuit, for the details not fully described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0076] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A transient response control circuit, characterized in that: The device comprises a first comparison module, a second comparison module, a logic module and a voltage regulation module, wherein the first comparison module is electrically connected to the second comparison module, the logic module and the voltage regulation module respectively, the second comparison module is electrically connected to the voltage regulation module, the first comparison module, the second comparison module and the voltage regulation module are all used to be electrically connected to a loop compensation circuit in a voltage converter, and the logic module is used to be electrically connected to a signal generating circuit in the voltage converter and a trigger circuit in the voltage converter respectively; When the output voltage of the voltage converter increases to a first preset value, the first comparison module is used to output a first comparison signal, and the logic module is used to output a first logic signal according to the first comparison signal and the clock signal output by the signal generating circuit, wherein the first logic signal is used to indicate that the output voltage of the voltage converter decreases; When the output voltage of the voltage converter decreases to a second preset value, the second comparison module is used to output a second comparison signal, and the voltage regulation module is used to increase the node voltage according to the second comparison signal to increase the output voltage of the voltage converter, wherein the node voltage is the voltage of the common end of the voltage regulation module and the loop compensation circuit; The first comparison module includes a first comparator, a first input end of the first comparator is electrically connected to the second comparison module and the first end of the compensation resistor in the loop compensation circuit, a second input end of the first comparator is electrically connected to the second comparison module, the second end of the compensation resistor, the voltage regulation module and the first end of the compensation capacitor in the loop compensation circuit, and an output end of the first comparator is electrically connected to the logic module.

2. The transient response control circuit according to claim 1, characterized in that: The second comparison module includes a second comparator, a first input end of the second comparator is electrically connected to the first comparison module and the first end of the compensation resistor in the loop compensation circuit, a second input end of the second comparator is electrically connected to the first comparison module, the second end of the compensation resistor, the voltage regulation module and the first end of the compensation capacitor in the loop compensation circuit, and an output end of the second comparator is electrically connected to the voltage regulation module.

3. The transient response control circuit according to claim 1, characterized in that: The logic module includes a NOR gate, a first input end of the NOR gate is electrically connected to the first comparison module, a second input end of the NOR gate is used to be electrically connected to the signal generating circuit, and an output end of the NOR gate is used to be electrically connected to the trigger circuit.

4. The transient response control circuit according to claim 1, characterized in that: The voltage regulating module comprises a first switch unit, a voltage generating unit and a current output unit, the first switch unit is electrically connected to the first comparison module, the second comparison module, the loop compensation circuit and the voltage generating unit respectively, and the voltage generating unit is electrically connected to the current output unit; The current output unit is used to output a first current, the voltage generating unit is used to output a first voltage to the first switch unit according to the first current, and the first switch unit is used to be turned on according to the second comparison signal and transmit the first voltage to the loop compensation circuit.

5. The transient response control circuit according to claim 4, characterized in that: The first switch unit includes a first switch tube, a gate of the first switch tube is electrically connected to the second comparison module, a source of the first switch tube is used to be electrically connected to the loop compensation circuit, and a drain of the first switch tube is electrically connected to the voltage generating unit.

6. The transient response control circuit according to claim 4, characterized in that: The voltage generating unit includes a first resistor, a second switch tube and a third switch tube, the first end of the first resistor is electrically connected to the source of the third switch tube, the second end of the first resistor is grounded, the gate of the second switch tube is electrically connected to the gate of the third switch tube, the drain of the third switch tube and the current output unit respectively, the source of the second switch tube is electrically connected to the first switch unit, and the drain of the second switch tube is used to be electrically connected to the first power supply.

7. The transient response control circuit according to claim 4, characterized in that: The current output unit includes a first current source, a first end of the first current source is used to be electrically connected to a first power source, and a second end of the first current source is electrically connected to the voltage generating unit.

8. The transient response control circuit according to claim 4, characterized in that: The current output unit includes a second resistor, a fourth switch tube, a fifth switch tube, a sixth switch tube, a seventh switch tube and an eighth switch tube. The first end of the second resistor is used to receive the output voltage of the voltage converter. The second end of the second resistor is electrically connected to the source of the fourth switch tube. The gate of the fourth switch tube is used to receive the input voltage of the voltage converter. The drain of the fourth switch tube is electrically connected to the drain of the fifth switch tube, the gate of the fifth switch tube and the gate of the sixth switch tube respectively. The drain of the sixth switch tube is electrically connected to the drain of the seventh switch tube, the gate of the seventh switch tube and the gate of the eighth switch tube respectively. The source of the sixth switch tube and the source of the fifth switch tube are both grounded. The source of the eighth switch tube and the source of the seventh switch tube are both used to receive the input voltage of the voltage converter. The drain of the eighth switch tube is electrically connected to the voltage generating unit.

9. A voltage converter, characterized in that: The invention comprises the transient response control circuit as described in any one of claims 1 to 8.

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