Transient response boost circuit and dc-dc converter

Abstract

The application belongs to the technical field of electronic circuits, and provides a transient response improvement circuit and a DC-DC converter. The transient response improvement circuit comprises a transconductance amplification module, a current module and a coupling module, the transconductance amplification module is connected with the coupling module, the current module and the common end of a first feedback resistor and a second feedback resistor in the DC-DC converter respectively, the current module is connected with the output end of an error amplifier in the DC-DC converter, and the coupling module is connected with the common end of the first feedback resistor and an output capacitor in the DC-DC converter. The application can improve the transient response of the DC-DC converter without affecting the loop stability. When the load of the DC-DC converter jumps, the circuit outputs a current to the output end of the error amplifier, so that the error control signal changes rapidly, the inductance current peak value is changed rapidly, the change of the load is adapted, the fluctuation of the output voltage is reduced, and the time for stabilizing the output is shortened.

Description

Technical Field

[0001] This application belongs to the field of electronic circuit technology, and in particular relates to a transient response enhancement circuit and a DC-DC converter. Background Technology

[0002] DC-DC (Direct Current-to-Direct Current) converters utilize inductors to continuously store and release energy, providing a stable output voltage or current. They are now widely used in the power supply architectures of various electronic products. To improve the transient response speed of DC-DC converters, existing technologies optimize the loop compensation network or the transconductance of the error amplifier, increasing the loop bandwidth to improve response speed. However, this approach can negatively impact system stability. Furthermore, because boost converters have a right-half-plane zero, this zero shifts to lower frequencies as the load or duty cycle increases. This right-half-plane zero limits the converter's loop bandwidth, degrading its stability and transient response. Summary of the Invention

[0003] This application provides a transient response enhancement circuit and a DC-DC converter, which can solve the problem that the system stability is easily deteriorated when the transient response of a DC-DC converter is improved by increasing the loop bandwidth in the prior art. In particular, for boost DC-DC converters, the right half-plane zero point will move to a lower frequency as the load or duty cycle increases, thereby limiting the loop bandwidth and further causing the system stability and transient response to deteriorate.

[0004] In a first aspect, embodiments of this application provide a transient response enhancement circuit, including a transconductance amplification module, a current module, and a coupling module. The transconductance amplification module is connected to the coupling module, the current module, and the common terminal of the first feedback resistor and the second feedback resistor in the DC-DC converter, respectively. The current module is connected to the output terminal of the error amplifier in the DC-DC converter, and the coupling module is connected to the common terminal of the first feedback resistor and the output capacitor in the DC-DC converter.

[0005] When the load current of the DC-DC converter changes, the coupling module is used to output a coupling voltage to the transconductance amplification module according to the change in the output voltage of the DC-DC converter; the transconductance amplification module is used to output a first signal according to the reference voltage, the feedback voltage of the DC-DC converter and the coupling voltage; the current module is used to output a first current according to the first signal, so as to make the error control signal output by the error amplifier change rapidly;

[0006] When the coupling ends and the output voltage does not reach the preset voltage, the transconductance amplification module continues to output a first signal based on the reference voltage and the feedback voltage, so that the current module continues to output a first current, thereby causing the error control signal to continue to adjust; when the output voltage reaches the preset voltage, the transconductance amplification module stops outputting the first signal, thereby causing the current module to stop outputting the first current.

[0007] In one possible implementation of the first aspect, the transconductance amplification module includes a first transconductance amplification unit and a second transconductance amplification unit. The first transconductance amplification unit is connected to the coupling module, the current module, the second transconductance amplification unit, and the common terminal of the first feedback resistor and the second feedback resistor in the DC-DC converter. The second transconductance amplification unit is connected to the current module. The first signal includes a first sub-signal, a second sub-signal, a third sub-signal, and a fourth sub-signal. The first current includes a pull-up current and a pull-down current. The coupling voltage includes a first coupling sub-voltage and a second coupling sub-voltage.

[0008] When the load current of the DC-DC converter increases, the coupling module is used to output a first coupling sub-voltage to the first transconductance amplification unit and the second transconductance amplification unit respectively according to the reduced output voltage; the first transconductance amplification unit is used to output a first sub-signal according to the reference voltage, the feedback voltage and the first coupling sub-voltage; the second transconductance amplification unit is used to output a second sub-signal according to the reference voltage, the feedback voltage and the first coupling sub-voltage; the current module is used to output a pull-up current according to the first sub-signal and the second sub-signal to make the error control signal rise rapidly;

[0009] When the coupling ends and the output voltage is less than the preset voltage, the first transconductance amplification unit continues to output a first sub-signal based on the reference voltage and the feedback voltage, and the second transconductance amplification unit continues to output a second sub-signal based on the reference voltage and the feedback voltage, so that the current module continues to output pull-up current, thereby causing the error control signal to continue to rise; when the output voltage reaches the preset voltage, the first transconductance amplification unit stops outputting the first sub-signal, the second transconductance amplification unit stops outputting the second sub-signal, thereby causing the current module to stop outputting pull-up current.

[0010] In one possible implementation of the first aspect, when the load current of the DC-DC converter decreases, the coupling module is configured to output a second coupling sub-voltage to the first transconductance amplification unit and the second transconductance amplification unit respectively according to the increased output voltage; the first transconductance amplification unit is configured to output a third sub-signal according to the reference voltage, the feedback voltage and the second coupling sub-voltage; the second transconductance amplification unit is configured to output a fourth sub-signal according to the reference voltage, the feedback voltage and the second coupling sub-voltage; the current module is configured to output a pull-down current according to the third sub-signal and the fourth sub-signal to rapidly reduce the error control signal;

[0011] When the coupling ends and the output voltage is greater than the preset voltage, the first transconductance amplification unit continues to output a third sub-signal based on the reference voltage and the feedback voltage, and the second transconductance amplification unit continues to output a fourth sub-signal based on the reference voltage and the feedback voltage, so that the current module continues to output pull-down current, thereby causing the error control signal to continue to decrease; when the output voltage reaches the preset voltage, the first transconductance amplification unit stops outputting the third sub-signal, the second transconductance amplification unit stops outputting the fourth sub-signal, thereby causing the current module to stop outputting pull-down current.

[0012] In one possible implementation of the first aspect, the first transconductance amplification unit includes a first transconductance amplifier, the non-inverting terminal of the first transconductance amplifier being connected to the common terminal of the first feedback resistor and the second feedback resistor in the coupling module, the second transconductance amplification unit, and the DC-DC converter, respectively, the inverting terminal of the first transconductance amplifier being used to receive a reference voltage, and the output terminal of the first transconductance amplifier being connected to the current module.

[0013] In one possible implementation of the first aspect, the second transconductance amplification unit includes a second transconductance amplifier, the non-inverting terminal of the second transconductance amplifier being connected to the common terminal of the first feedback resistor and the second feedback resistor in the first transconductance amplification unit, the coupling module, and the DC-DC converter, respectively, the inverting terminal of the second transconductance amplifier being used to receive a reference voltage, and the output terminal of the second transconductance amplifier being connected to the current module.

[0014] In one possible implementation of the first aspect, the current module includes a pull-up current unit and a pull-down current unit, the pull-up current unit being connected to the output terminals of the first transconductance amplifier unit, the pull-down current unit and the error amplifier, respectively, and the pull-down current unit being connected to the second transconductance amplifier unit;

[0015] When the load current of the DC-DC converter increases, the pull-down current unit stops working according to the second sub-signal, and the pull-up current unit outputs a pull-up current according to the first sub-signal to make the error control signal rise rapidly. When the coupling ends and the output voltage is less than a preset voltage, the pull-down current unit still stops working according to the second sub-signal, and the pull-up current unit continues to output a pull-up current according to the first sub-signal to make the error control signal continue to rise. When the output voltage reaches the preset voltage, the first transconductance amplification unit stops outputting the first sub-signal, thereby causing the pull-up current unit to stop outputting the pull-up current.

[0016] When the load current of the DC-DC converter decreases, the pull-up current unit stops working according to the third sub-signal, and the pull-down current unit outputs a pull-down current according to the fourth sub-signal to rapidly reduce the error control signal. When the coupling ends and the output voltage is greater than a preset voltage, the pull-up current unit still stops working according to the third sub-signal, and the pull-down current unit continues to output a pull-down current according to the fourth sub-signal to further reduce the error control signal. When the output voltage reaches the preset voltage, the second transconductance amplification unit stops outputting the fourth sub-signal, thereby causing the pull-down current unit to stop outputting the pull-down current.

[0017] In one possible implementation of the first aspect, the pull-up current unit includes a first transistor and a second transistor, the gate of the first transistor is connected to the drain of the first transistor, the gate of the second transistor and the first transconductance amplification unit, the source of the first transistor and the source of the second transistor both receive a power supply voltage, and the drain of the second transistor is connected to the output terminal of the pull-down current unit and the error amplifier.

[0018] In one possible implementation of the first aspect, the pull-down current unit includes a third transistor and a fourth transistor, the gate of the third transistor being connected to the drain of the third transistor, the gate of the fourth transistor and the second transconductance amplification unit, respectively, the source of the third transistor and the source of the fourth transistor being grounded, and the drain of the fourth transistor being connected to the output terminal of the pull-up current unit and the error amplifier, respectively.

[0019] In one possible implementation of the first aspect, the coupling module includes a first capacitor, a first terminal of which is connected to a common terminal of a first feedback resistor and an output capacitor in the DC-DC converter, and a second terminal of which is connected to a common terminal of a transconductance amplification module and a common terminal of a first feedback resistor and a second feedback resistor in the DC-DC converter.

[0020] Secondly, embodiments of this application provide a DC-DC converter, including the transient response enhancement circuit described in any one of the first aspects.

[0021] Thirdly, embodiments of this application provide a switching power supply chip, including the DC-DC converter described in any one of the second aspects.

[0022] Fourthly, embodiments of this application also provide an electronic device, including the switching power supply chip described in any one of the third aspects.

[0023] The beneficial effects of the embodiments in this application compared with the prior art are:

[0024] This application provides a transient response enhancement circuit, including a transconductance amplification module, a current module, and a coupling module. The transconductance amplification module is connected to the coupling module, the current module, and the common terminal of the first feedback resistor and the second feedback resistor in the DC-DC converter. The current module is connected to the output terminal of the error amplifier in the DC-DC converter. The coupling module is connected to the common terminal of the first feedback resistor and the output capacitor in the DC-DC converter.

[0025] When the load current of the DC-DC converter changes, its output voltage also changes. At this time, the coupling module outputs a coupling voltage to the transconductance amplification module based on the change in output voltage, specifically, rapidly coupling the change in output voltage to the transconductance amplification module. This coupling voltage is directly superimposed on the feedback voltage, making the difference between the superimposed feedback voltage and the reference voltage more significant. Therefore, the transconductance amplification module outputs a first signal based on the reference voltage, the feedback voltage of the DC-DC converter, and the coupling voltage. The current module outputs a first current based on the first signal, causing the error control signal output by the error amplifier to change rapidly, thereby causing the peak value of the inductor current in the DC-DC converter to change rapidly, thus adapting to changes in the load.

[0026] When the coupling ends and the output voltage does not reach the preset voltage, that is, during the output voltage recovery process, the feedback voltage never reaches the reference voltage, meaning there is still a difference between the feedback voltage and the reference voltage. Therefore, the transconductance amplification module continues to output the first signal based on the reference voltage and the feedback voltage, so that the current module continues to output the first current, thereby causing the error control signal to continue to adjust. When the output voltage reaches the preset voltage, the transconductance amplification module stops outputting the first signal, thereby causing the current module to stop outputting the first current, and the output voltage finally remains in a stable state.

[0027] This application can improve the transient response of a DC-DC converter without affecting loop stability. When the load of the DC-DC converter changes, the circuit outputs current to the output of the error amplifier, causing the error control signal to change rapidly. This rapidly changes the peak value of the inductor current to adapt to the load change, reduce output voltage fluctuations, and shorten the output stabilization time.

[0028] In summary, the control method for the transient response enhancement circuit provided in this application is simple and efficient, and does not affect the bandwidth and stability of the loop. It effectively solves the problem in the prior art that increasing the bandwidth to enhance the transient response leads to a decrease in system stability. In particular, it solves the problem that in boost DC-DC converters, the zero point of the right half-plane will move to a lower frequency as the load or duty cycle increases, thereby limiting the loop bandwidth and further deteriorating the system stability and transient response.

[0029] It is understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant descriptions in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a circuit connection diagram of a boost DC-DC converter;

[0032] Figure 2 This is a schematic diagram of a transient response enhancement circuit provided in an embodiment of this application;

[0033] Figure 3 This is a schematic diagram of a transient response enhancement circuit provided in another embodiment of this application;

[0034] Figure 4 This is a circuit connection diagram of a transient response enhancement circuit provided in an embodiment of this application;

[0035] Figure 5 This is a schematic diagram comparing the key waveforms of boost DC-DC converters with and without transient response enhancement circuits.

[0036] In the figure: 10, transient response enhancement circuit; 101, transconductance amplification module; 1011, first transconductance amplification unit; 1012, second transconductance amplification unit; 102, current module; 1021, pull-up current unit; 1022, pull-down current unit; 103, coupling module; 20, DC-DC converter. Detailed Implementation

[0037] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0038] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0039] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0040] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if [the described condition or event] is detected" may be interpreted, depending on the context, as "once determined," "in response to determination," "once [the described condition or event] is detected," or "in response to detection of [the described condition or event]."

[0041] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0042] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0043] To address the problem that increasing the loop bandwidth to improve the transient response of a DC-DC converter in existing technologies can easily lead to a decrease in system stability, especially for boost DC-DC converters, where the right half-plane zero point shifts to lower frequencies as the load or duty cycle increases, thus limiting the loop bandwidth and further deteriorating system stability and transient response, this application proposes a transient response enhancement circuit, including a transconductance amplification module, a current module, and a coupling module. The transconductance amplification module is connected to the coupling module, the current module, and the common terminal of the first feedback resistor and the second feedback resistor in the DC-DC converter, respectively. The current module is connected to the output terminal of the error amplifier in the DC-DC converter, and the coupling module is connected to the common terminal of the first feedback resistor and the output capacitor in the DC-DC converter.

[0044] When the load current of the DC-DC converter changes, its output voltage also changes. At this time, the coupling module outputs a coupling voltage to the transconductance amplification module based on the change in output voltage, specifically, rapidly coupling the change in output voltage to the transconductance amplification module. This coupling voltage is directly superimposed on the feedback voltage, making the difference between the superimposed feedback voltage and the reference voltage more significant. Therefore, the transconductance amplification module outputs a first signal based on the reference voltage, the feedback voltage of the DC-DC converter, and the coupling voltage. The current module outputs a first current based on the first signal, causing the error control signal output by the error amplifier to change rapidly, thereby causing the peak value of the inductor current in the DC-DC converter to change rapidly, thus adapting to changes in the load.

[0045] When the coupling ends and the output voltage does not reach the preset voltage, that is, during the output voltage recovery process, the feedback voltage never reaches the reference voltage, meaning there is still a difference between the feedback voltage and the reference voltage. Therefore, the transconductance amplification module continues to output the first signal based on the reference voltage and the feedback voltage, so that the current module continues to output the first current, thereby causing the error control signal to continue to adjust. When the output voltage reaches the preset voltage, the transconductance amplification module stops outputting the first signal, thereby causing the current module to stop outputting the first current, and the output voltage finally remains in a stable state.

[0046] This application can improve the transient response of a DC-DC converter without affecting loop stability. When the load of the DC-DC converter changes, the circuit outputs current to the output of the error amplifier, causing the error control signal to change rapidly. This rapidly changes the peak value of the inductor current to adapt to the load change, reduce output voltage fluctuations, and shorten the output stabilization time.

[0047] To make the technical solution of this application clearer, the basic working principle of the boost DC-DC converter will be explained below as an example; however, it should be noted that this application is not only applicable to boost DC-DC converters, but can also be applied to other types of DC-DC converters.

[0048] Figure 1 A circuit connection diagram for a boost DC-DC converter is shown. Figure 1 As shown, the boost DC-DC converter includes an error amplifier Gm, a PWM comparator, and a current sampling circuit (specifically referring to...). Figure 1 Sampling resistor R S (Circuit at the location), slope compensation circuit (specifically referring to) Figure 1 Mid-slope compensation signal V SE The circuit at the point of connection includes a logic control module, an inductor L, a switching transistor S, a diode D, and a first feedback resistor R. FB1 Second feedback resistor R FB2 Output capacitor C OUT and load resistance R OUT Among them, the first feedback resistor R FB1 Second feedback resistor R FB2 The common terminal is used to output the feedback voltage V. FB First feedback resistor R FB1 and output capacitor C OUT The common terminal is used to output the output voltage V. OUT .

[0049] Under peak current mode control, when the output voltage V OUT When the voltage changes, in the voltage loop, the first feedback resistor R FB1 Second feedback resistor R FB2 The feedback voltage V obtained by voltage division FB It will also change accordingly; feedback voltage V FB With reference voltage V REF The error signal V is obtained by inputting it into the error amplifier Gm and then comparing and amplifying it. C In the current loop, the current sampling circuit uses a sampling resistor R. S The current signal is converted into a voltage signal and compared with the slope compensation signal V. SE Superimposed, the sampled signal V is obtained. S; Sampled signal V S The signal, along with the error control signal Vc, is input to the PWM comparator. After comparison, a modulation signal is generated. The logic control module then uses the oscillator signal Vc to generate the modulation signal. CLK The duty cycle of the switching transistor S is adjusted according to the modulation signal to ensure the output voltage V. OUT Stablize.

[0050] To illustrate the technical solution described in this application, specific embodiments are provided below.

[0051] Figure 2 A schematic diagram of a transient response enhancement circuit 10 provided in an embodiment of this application is shown. Figure 2 As shown, the transient response boosting circuit 10 includes a transconductance amplification module 101, a current module 102, and a coupling module 103. The transconductance amplification module 101 is connected to the coupling module 103, the current module 102, and the common terminal of the first feedback resistor and the second feedback resistor in the DC-DC converter 20. The current module 102 is connected to the output terminal of the error amplifier in the DC-DC converter 20. The coupling module 103 is connected to the common terminal of the first feedback resistor and the output capacitor in the DC-DC converter 20. In this embodiment, the DC-DC converter 20 is a boost DC-DC converter.

[0052] Specifically, when the load current of the DC-DC converter 20 changes, its output voltage V OUT It will also change, at which point the coupling module 103 will adjust according to the output voltage V. OUT The change in voltage outputs a coupling voltage to the transconductance amplification module 101, specifically, the output voltage V... OUT The change is rapidly coupled to the transconductance amplification module 101. This coupling voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD With reference voltage V REF There is a more significant difference between them, therefore the transconductance amplification module 101 adjusts the voltage based on the reference voltage V. REF The feedback voltage V of the DC-DC converter 20 FB The coupling voltage outputs a first signal. The current module 102 outputs a first current based on the first signal, so that the error control signal V output by the error amplifier... C The rapid changes cause the peak value of the inductor current in the DC-DC converter 20 to change rapidly, thereby adapting to the load changes. It should be noted that the first signal output by the transconductance amplifier module 101 is essentially a current signal, which changes the voltage of the key node inside the current module 102, thereby causing the current module 102 to output the first current.

[0053] When the coupling ends, the output voltage V OUTWhen the preset voltage is not reached, i.e., when the output voltage V... OUT During the recovery process, the feedback voltage V FB The reference voltage V was never reached. REF That is, the feedback voltage V FB With reference voltage V REF There is still a difference between them, so the transconductance amplification module 101 adjusts the voltage according to the reference voltage V. REF and feedback voltage V FB The first signal continues to be output so that the current module 102 continues to output the first current, thereby causing the error control signal V to continue to output the first current. C Continue adjusting. When the output voltage V OUT When the preset voltage is reached, the transconductance amplifier module 101 stops outputting the first signal, which in turn causes the current module 102 to stop outputting the first current, and the output voltage V... OUT It eventually stabilized.

[0054] This application can improve the transient response of the DC-DC converter 20 without affecting loop stability. When the load of the DC-DC converter 20 changes, it outputs current to the output of the error amplifier, thereby affecting the error control signal V. C Rapid changes in load thus quickly alter the peak inductor current, adapting to load variations and reducing the output voltage V. OUT This reduces fluctuations and shortens the time it takes for the output to stabilize.

[0055] In summary, the control method of the transient response enhancement circuit 10 provided in this application is simple and efficient, and does not affect the bandwidth and stability of the loop. It effectively solves the problem in the prior art that increasing the bandwidth to enhance the transient response leads to a decrease in system stability. In particular, it solves the problem that in boost DC-DC converters, the zero point of the right half-plane will move to a lower frequency as the load or duty cycle increases, thereby limiting the loop bandwidth and further deteriorating the system stability and transient response.

[0056] In one embodiment of this application, such as Figure 3 As shown, the transconductance amplification module 101 includes a first transconductance amplification unit 1011 and a second transconductance amplification unit 1012. The first transconductance amplification unit 1011 is connected to the coupling module 103, the current module 102, the second transconductance amplification unit 1012, and the common terminal of the first feedback resistor and the second feedback resistor in the DC-DC converter 20. The second transconductance amplification unit 1012 is connected to the current module 102. The first signal includes a first sub-signal, a second sub-signal, a third sub-signal, and a fourth sub-signal. The first current includes a pull-up current and a pull-down current. The coupling voltage includes a first coupling sub-voltage and a second coupling sub-voltage.

[0057] Specifically, when the load current of DC-DC converter 20 increases (i.e., when the load of DC-DC converter 20 suddenly becomes heavier), the output voltage V OUT The voltage will decrease, at which point the coupling module 103 will adjust the output voltage V based on the decrease. OUT The first coupler voltage is output to the first transconductance amplification unit 1011 and the second transconductance amplification unit 1012 respectively, specifically by reducing the output voltage V. OUT Rapidly coupled to the first transconductance amplification unit 1011 and the second transconductance amplification unit 1012; the voltage of the first coupler is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly less than the reference voltage V REF Therefore, the first transconductance amplifier unit 1011 is based on the reference voltage V REF Feedback voltage V FB The first sub-signal is output based on the first coupling sub-voltage; the second transconductance amplification unit 1012 outputs the first sub-signal based on the reference voltage V. REF Feedback voltage V FB The first coupling sub-voltage outputs a second sub-signal, both of which are pull-down currents; the current module 102 outputs a pull-up current based on the first and second sub-signals, so that the error control signal V... C It can rapidly increase in height to adapt to heavier loads.

[0058] When the coupling ends, the output voltage V OUT When the voltage is less than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always less than the reference voltage V REF Therefore, the first transconductance amplifier unit 1011 is based on the reference voltage V REF and feedback voltage V FB The first sub-signal continues to be output; the second transconductance amplification unit 1012 outputs the first sub-signal according to the reference voltage V. REF and feedback voltage V FB The second sub-signal continues to be output, causing the current module 102 to continue outputting pull-up current, thereby causing the error control signal Vc to continue to rise. When the output voltage V... OUT When the preset voltage is reached, the first transconductance amplifier unit 1011 stops outputting the first sub-signal, and the second transconductance amplifier unit 1012 stops outputting the second sub-signal, thereby causing the current module 102 to stop outputting the pull-up current.

[0059] When the load current of DC-DC converter 20 decreases (i.e., when the load of DC-DC converter 20 suddenly becomes lighter), the output voltage V OUT The voltage will rise, at which point the coupling module 103 will adjust the output voltage V based on the increased voltage. OUTThe second coupler voltage is output to the first transconductance amplification unit 1011 and the second transconductance amplification unit 1012 respectively, specifically by increasing the output voltage V. OUT The second coupler voltage is rapidly coupled to the first transconductance amplification unit 1011 and the second transconductance amplification unit 1012; the second coupler voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly greater than the reference voltage V REF Therefore, the first transconductance amplifier unit 1011 is based on the reference voltage V REF Feedback voltage V FB The second coupling sub-voltage outputs the third sub-signal; the second transconductance amplification unit 1012 outputs the third sub-signal based on the reference voltage V. REF Feedback voltage V FB The second coupling sub-voltage outputs the fourth sub-signal, and both the third and fourth sub-signals are pull-up currents; the current module 102 outputs a pull-down current based on the third and fourth sub-signals to rapidly reduce the error control signal Vc, thereby adapting to a lighter load.

[0060] When the coupling ends, the output voltage V OUT When the voltage is greater than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always greater than the reference voltage V REF Therefore, the first transconductance amplifier unit 1011 is based on the reference voltage V REF and feedback voltage V FB The third sub-signal continues to be output; the second transconductance amplifier unit 1012 outputs the third sub-signal based on the reference voltage V. REF and feedback voltage V FB The fourth sub-signal continues to be output, causing the current module 102 to continue outputting pull-down current, thereby further reducing the error control signal Vc. When the output voltage V... OUT When the preset voltage is reached, the first transconductance amplifier unit 1011 stops outputting the third sub-signal, and the second transconductance amplifier unit 1012 stops outputting the fourth sub-signal, thereby causing the current module 102 to stop outputting the pull-down current.

[0061] In one embodiment of this application, such as Figure 3 As shown, the current module 102 includes a pull-up current unit 1021 and a pull-down current unit 1022. The pull-up current unit 1021 is connected to the output terminals of the first transconductance amplifier unit 1011, the pull-down current unit 1022 and the error amplifier, respectively. The pull-down current unit 1022 is connected to the second transconductance amplifier unit 1012.

[0062] Specifically, when the load current of DC-DC converter 20 increases (i.e., when the load of DC-DC converter 20 suddenly becomes heavier), the output voltage VOUT The voltage will decrease, at which point the coupling module 103 will adjust the output voltage V based on the decrease. OUT The first coupler voltage is output to the first transconductance amplification unit 1011 and the second transconductance amplification unit 1012 respectively; the first coupler voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly less than the reference voltage V REF Therefore, the first transconductance amplifier unit 1011 is based on the reference voltage V REF Feedback voltage V FB The first sub-signal is output based on the first coupling sub-voltage; the second transconductance amplification unit 1012 outputs the first sub-signal based on the reference voltage V. REF Feedback voltage V FB The first sub-signal is coupled to the first sub-voltage, and both the first and second sub-signals are pull-down currents. Because the second sub-signal is a pull-down current, it changes the critical node voltage inside the pull-down current unit 1022, causing the pull-down current unit 1022 to stop working. Similarly, because the first sub-signal is a pull-down current, it changes the critical node voltage inside the pull-up current unit 1021, causing the pull-up current unit 1021 to output a pull-up current, thereby enabling the error control signal V to... C Rapidly increase in altitude to eventually adapt to heavier loads;

[0063] When the coupling ends, the output voltage V OUT When the voltage is less than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always less than the reference voltage V REF Therefore, the first transconductance amplifier unit 1011 is based on the reference voltage V REF and feedback voltage V FB The first sub-signal continues to be output; the second transconductance amplification unit 1012 outputs the first sub-signal according to the reference voltage V. REF and feedback voltage V FB The second sub-signal continues to be output; the pull-down current unit 1022 stops working according to the second sub-signal; the pull-up current unit 1021 continues to output the pull-up current according to the first sub-signal, so that the error control signal V... C Continue to rise. When the output voltage V OUT When the preset voltage is reached, the first transconductance amplifier unit 1011 stops outputting the first sub-signal, thereby causing the pull-up current unit 1021 to stop outputting the pull-up current. At the same time, the second transconductance amplifier unit 1012 stops outputting the second sub-signal.

[0064] When the load current of DC-DC converter 20 decreases (i.e., when the load of DC-DC converter 20 suddenly becomes lighter), the output voltage V OUTThe voltage will rise, at which point the coupling module 103 will adjust the output voltage V based on the increased voltage. OUT The second coupler voltage is output to the first transconductance amplification unit 1011 and the second transconductance amplification unit 1012 respectively; the second coupler voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly greater than the reference voltage V REF Therefore, the first transconductance amplifier unit 1011 is based on the reference voltage V REF Feedback voltage V FB The second coupling sub-voltage outputs the third sub-signal; the second transconductance amplification unit 1012 outputs the third sub-signal based on the reference voltage V. REF Feedback voltage V FB The second coupling sub-voltage outputs a fourth sub-signal. Both the third and fourth sub-signals are pull-up currents. Since the third sub-signal is a pull-up current, this pull-up changes the critical node voltage inside the pull-up current unit 1021, causing the pull-up current unit 1021 to stop working. Similarly, since the fourth sub-signal is a pull-up current, this pull-up changes the critical node voltage inside the pull-down current unit 1022, causing the pull-down current unit 1022 to output a pull-down current, thereby enabling the error control signal V to... C It decreases rapidly, eventually adapting to lighter loads.

[0065] When the coupling ends, the output voltage V OUT When the voltage is greater than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always greater than the reference voltage V REF Therefore, the first transconductance amplifier unit 1011 is based on the reference voltage V REF and feedback voltage V FB The third sub-signal continues to be output; the second transconductance amplifier unit 1012 outputs the third sub-signal based on the reference voltage V. REF and feedback voltage V FB The fourth sub-signal continues to be output; the pull-up current unit 1021 stops working according to the third sub-signal; the pull-down current unit 1022 continues to output pull-down current according to the fourth sub-signal, so that the error control signal V... C Continue to decrease. When the output voltage V OUT When the preset voltage is reached, the second transconductance amplifier unit 1012 stops outputting the fourth sub-signal, thereby causing the pull-down current unit 1022 to stop outputting the pull-down current. At the same time, the first transconductance amplifier unit 1011 stops outputting the third sub-signal.

[0066] In one embodiment of this application, such as Figure 4As shown, the first transconductance amplifier unit 1011 includes a first transconductance amplifier gm1. The non-inverting input of the first transconductance amplifier gm1 is connected to the coupling module 103, the second transconductance amplifier unit 1012, and the common terminal of the first feedback resistor and the second feedback resistor in the DC-DC converter 20. The inverting input of the first transconductance amplifier gm1 is used to receive the reference voltage V. REF The output terminal of the first transconductance amplifier gm1 is connected to the current module 102.

[0067] Specifically, when the load current of DC-DC converter 20 increases (i.e., when the load of DC-DC converter 20 suddenly becomes heavier), the output voltage V OUT The voltage will decrease, at which point the coupling module 103 will adjust the output voltage V based on the decrease. OUT The first coupler voltage is output to the non-inverting input of the first transconductance amplifier gm1; this first coupler voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly less than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF Feedback voltage V FB The first sub-signal is output along with the first coupling voltage.

[0068] When the coupling ends, the output voltage V OUT When the voltage is less than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always less than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF and feedback voltage V FB Continue outputting the first sub-signal. When the output voltage V OUT When the preset voltage is reached, the first transconductance amplifier gm1 stops outputting the first sub-signal.

[0069] When the load current of DC-DC converter 20 decreases (i.e., when the load of DC-DC converter 20 suddenly becomes lighter), the output voltage V OUT The voltage will rise, at which point the coupling module 103 will adjust the output voltage V based on the increased voltage. OUT A second coupler voltage is output to the non-inverting input of the first transconductance amplifier gm1; this second coupler voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly greater than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF Feedback voltage V FB The second coupling voltage outputs the third sub-signal.

[0070] When the coupling ends, the output voltage V OUT When the voltage is greater than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always greater than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF and feedback voltage V FB Continue outputting the third sub-signal. When the output voltage V OUT When the preset voltage is reached, the first transconductance amplifier gm1 stops outputting the third sub-signal.

[0071] In one embodiment of this application, such as Figure 4 As shown, the second transconductance amplifier unit 1012 includes a second transconductance amplifier gm2. The non-inverting input of the second transconductance amplifier gm2 is connected to the common terminal of the first feedback resistor and the second feedback resistor in the first transconductance amplifier unit 1011, the coupling module 103, and the DC-DC converter 20, respectively. The inverting input of the second transconductance amplifier gm2 is used to receive the reference voltage V. REF The output terminal of the second transconductance amplifier gm2 is connected to the current module 102.

[0072] Specifically, when the load current of DC-DC converter 20 increases (i.e., when the load of DC-DC converter 20 suddenly becomes heavier), the output voltage V OUT The voltage will decrease, at which point the coupling module 103 will adjust the output voltage V based on the decrease. OUT The first coupler voltage is output to the non-inverting input of the second transconductance amplifier gm2; this first coupler voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly less than the reference voltage V REF Therefore, the second transconductance amplifier gm2 is based on the reference voltage V. REF Feedback voltage V FB The voltage of the first coupling element outputs the second sub-signal.

[0073] When the coupling ends, the output voltage V OUT When the voltage is less than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always less than the reference voltage V REF Therefore, the second transconductance amplifier gm2 is based on the reference voltage V. REF and feedback voltage V FB Continue outputting the second sub-signal. When the output voltage V OUT When the preset voltage is reached, the second transconductance amplifier gm2 stops outputting the second sub-signal.

[0074] When the load current of DC-DC converter 20 decreases (i.e., when the load of DC-DC converter 20 suddenly becomes lighter), the output voltage V OUT The voltage will rise, at which point the coupling module 103 will adjust the output voltage V based on the increased voltage. OUT The second coupler voltage is output to the non-inverting input of the second transconductance amplifier gm2; this second coupler voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly greater than the reference voltage V REF Therefore, the second transconductance amplifier gm2 is based on the reference voltage V. REF Feedback voltage V FB The second coupling voltage outputs the fourth sub-signal.

[0075] When the coupling ends, the output voltage V OUT When the voltage is greater than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always greater than the reference voltage V REF Therefore, the second transconductance amplifier gm2 is based on the reference voltage V. REF and feedback voltage V FB Continue outputting the fourth sub-signal. When the output voltage V OUT When the preset voltage is reached, the second transconductance amplifier gm2 stops outputting the fourth sub-signal.

[0076] It should be noted that, in order to ensure that the DC-DC converter 20 can operate normally in steady state, the transient response enhancement circuit 10 proposed in this application artificially introduces an offset in the input voltage in the first transconductance amplifier gm1 and the second transconductance amplifier gm2, so that when the output voltage V OUT The transient response boosting circuit 10 will only start working and generate pull-up or pull-down current when the change is large enough.

[0077] In one embodiment of this application, such as Figure 4 As shown, the pull-up current unit 1021 includes a first transistor M1 and a second transistor M2. The gate of the first transistor M1 is connected to the drain of the first transistor M1, the gate of the second transistor M2 and the first transconductance amplifier unit 1011, respectively. The source of the first transistor M1 and the source of the second transistor M2 both receive the power supply voltage VCC. The drain of the second transistor M2 is connected to the pull-down current unit 1022 and the output terminal of the error amplifier, respectively.

[0078] Specifically, when the load current of DC-DC converter 20 increases (i.e., when the load of DC-DC converter 20 suddenly becomes heavier), the output voltage V OUT The voltage will decrease, at which point the coupling module 103 will adjust the output voltage V based on the decrease. OUTThe first coupler voltage is output to the non-inverting inputs of the first transconductance amplifier gm1 and the second transconductance amplifier gm2, respectively; this first coupler voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly less than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF Feedback voltage V FB The first sub-signal is output by the first coupling sub-voltage, and the second transconductance amplifier gm2 outputs the first sub-signal based on the reference voltage V. REF Feedback voltage V FB The first coupling sub-voltage outputs a second sub-signal, both of which are pull-down currents. This pull-down current changes the critical node voltage inside the pull-down current unit 1022, causing the pull-down current unit 1022 to stop working. Simultaneously, this pull-down current pulls down the gate voltage of the first transistor M1, turning on the first transistor M1 and generating current. This current, after being mirrored by a current mirror, outputs a pull-up current (i.e., ...) to the output of the error amplifier. Figure 4 The dashed current flowing into the DC-DC converter 20 (to make the error control signal V) C It can rapidly increase in height to adapt to heavier loads.

[0079] When the coupling ends, the output voltage V OUT When the voltage is less than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always less than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF and feedback voltage V FB Continuing to output the first sub-signal, the second transconductance amplifier gm2 outputs the signal based on the reference voltage V. REF and feedback voltage V FB The second sub-signal continues to be output, and both the first and second sub-signals are pull-down currents. The pull-down current unit 1022 continues to operate based on this pull-down current. Simultaneously, this pull-down current continues to pull the gate voltage of the first transistor M1 low, causing the first transistor M1 to conduct and generate current. This current, after being mirrored by a current mirror, continues to output a pull-up current to the output of the error amplifier (i.e.,...). Figure 4 The dashed current flowing into the DC-DC converter 20 (to make the error control signal V) C Continue to rise. When the output voltage V OUT When the preset voltage is reached, the first transconductance amplifier gm1 stops outputting the first sub-signal, thereby causing the pull-up current unit 1021 to stop outputting the pull-up current; at the same time, the second transconductance amplifier unit 1012 stops outputting the second sub-signal.

[0080] When the load current of DC-DC converter 20 decreases (i.e., when the load of DC-DC converter 20 suddenly becomes lighter), the output voltage V OUT The voltage will rise, at which point the coupling module 103 will adjust the output voltage V based on the increased voltage. OUT The second coupler voltage is output to the non-inverting inputs of the first transconductance amplifier gm1 and the second transconductance amplifier gm2, respectively; this second coupler voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly greater than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF Feedback voltage V FB The second coupling sub-voltage outputs the third sub-signal, and the second transconductance amplifier gm2 outputs the third sub-signal based on the reference voltage V. REF Feedback voltage V FB The second coupling sub-voltage outputs a fourth sub-signal, while both the third and fourth sub-signals are pull-up currents. This pull-up current pulls the gate voltage of the first transistor M1 high, turning off the first transistor M1 and thus stopping the pull-up current unit 1021 from working. Simultaneously, this pull-up current changes the critical node voltage inside the pull-down current unit 1022, causing the pull-down current unit 1022 to output a pull-down current, thereby enabling the error control signal V to... C It decreases rapidly, eventually adapting to lighter loads.

[0081] When the coupling ends, the output voltage V OUT When the voltage is greater than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always greater than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF and feedback voltage V FB The third sub-signal continues to be output, and the second transconductance amplifier gm2 outputs the signal based on the reference voltage V. REF and feedback voltage V FB The fourth sub-signal continues to be output. Both the third and fourth sub-signals are pull-up currents. This pull-up current continues to pull the gate voltage of the first transistor M1 high, causing the first transistor M1 to turn off, and thus the pull-up current unit 1021 continues to stop working. The pull-down current unit 1022 continues to output a pull-down current according to the fourth sub-signal, thereby causing the error control signal V to... C Continue to decrease. When the output voltage V OUT When the preset voltage is reached, the first transconductance amplifier gm1 stops outputting the third sub-signal; at the same time, the second transconductance amplifier gm2 stops outputting the fourth sub-signal, thereby causing the pull-down current unit 1022 to stop outputting the pull-down current.

[0082] As can be seen from the above, when the load current of DC-DC converter 20 increases, and the output voltage V... OUT During the recovery process, the pull-down current unit 1022 remains inactive, while the pull-up current unit 1021 continuously outputs pull-up current; when the output voltage V OUT When the preset voltage is reached, the pull-up current unit 1021 stops outputting pull-up current. And when the load current of the DC-DC converter 20 decreases, and the output voltage V... OUT During the recovery process, the pull-up current unit 1021 remains inactive, while the pull-down current unit 1022 continuously outputs pull-down current; when the output voltage V OUT When the preset voltage is reached, the pull-down current unit 1022 stops outputting pull-down current.

[0083] In one embodiment of this application, such as Figure 4 As shown, the pull-down current unit 1022 includes a third transistor M3 and a fourth transistor M4. The gate of the third transistor M3 is connected to the drain of the third transistor M3, the gate of the fourth transistor M4, and the second transconductance amplifier unit 1012. The sources of the third transistor M3 and the fourth transistor M4 are both grounded. The drain of the fourth transistor M4 is connected to the pull-up current unit 1021 and the output terminal of the error amplifier.

[0084] Specifically, when the load current of DC-DC converter 20 increases (i.e., when the load of DC-DC converter 20 suddenly becomes heavier), the output voltage V OUT The voltage will decrease, at which point the coupling module 103 will adjust the output voltage V based on the decrease. OUT The first coupled voltage is output to the non-inverting inputs of the first transconductance amplifier gm1 and the second transconductance amplifier gm2, respectively; this first coupled voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly less than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF Feedback voltage V FB The first sub-signal is output by the first coupling sub-voltage, and the second transconductance amplifier gm2 outputs the first sub-signal based on the reference voltage V. REF Feedback voltage V FB The first coupling sub-voltage outputs a second sub-signal, both of which are pull-down currents. This pull-down current pulls down the gate voltage of the third transistor M3, turning it off and thus stopping the pull-down current unit 1022. Simultaneously, this pull-down current pulls down the gate voltage of the first transistor M1, turning it on and generating current. This current, after being mirrored by a current mirror, outputs a pull-up current (i.e., ...) to the output of the error amplifier. Figure 4The dashed current flowing into the DC-DC converter 20 (to make the error control signal V) C It can rapidly increase in height to adapt to heavier loads.

[0085] When the coupling ends, the output voltage V OUT When the voltage is less than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always less than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF and feedback voltage V FB Continuing to output the first sub-signal, the second transconductance amplifier gm2 outputs the signal based on the reference voltage V. REF and feedback voltage V FB The second sub-signal continues to be output, while both the first and second sub-signals are pull-down currents. This pull-down current continues to pull the gate voltage of the third transistor M3 low, turning it off, and thus the pull-down current unit 1022 continues to stop working. Simultaneously, this pull-down current continues to pull the gate voltage of the first transistor M1 low, turning it on and generating current. This current, after being mirrored by a current mirror, continues to output a pull-up current (i.e., ...) to the output of the error amplifier. Figure 4 The dashed current flowing into the DC-DC converter 20 (to make the error control signal V) C Continue to rise. When the output voltage V OUT When the preset voltage is reached, the second transconductance amplifier gm2 stops outputting the second sub-signal; at the same time, the first transconductance amplifier gm1 stops outputting the first sub-signal, thereby causing the pull-up current unit 1021 to stop outputting the pull-up current.

[0086] When the load current of DC-DC converter 20 decreases (i.e., when the load of DC-DC converter 20 suddenly becomes lighter), the output voltage V OUT The voltage will rise, at which point the coupling module 103 will adjust the output voltage V based on the increased voltage. OUT The second coupler voltage is output to the non-inverting inputs of the first transconductance amplifier gm1 and the second transconductance amplifier gm2, respectively; this second coupler voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly greater than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF Feedback voltage V FB The second coupling sub-voltage outputs the third sub-signal, and the second transconductance amplifier gm2 outputs the third sub-signal based on the reference voltage V. REF Feedback voltage V FBThe second coupling sub-voltage outputs a fourth sub-signal, and both the third and fourth sub-signals are pull-up currents. This pull-up current pulls up the gate voltage of the first transistor M1, turning it off and thus stopping the pull-up current unit 1021. Simultaneously, this pull-up current pulls up the gate voltage of the third transistor M3, turning it on and generating current. This current, after being mirrored by a current mirror, outputs a pull-down current (i.e., ...) to the output of the error amplifier. Figure 4 The dashed current flowing out of the DC-DC converter 20 causes the error control signal Vc to decrease rapidly, thereby adapting to a lighter load.

[0087] When the coupling ends, the output voltage V OUT When the voltage is greater than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always greater than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF and feedback voltage V FB The third sub-signal continues to be output, and the second transconductance amplifier gm2 outputs the signal based on the reference voltage V. REF and feedback voltage V FB The fourth sub-signal continues to be output. Both the third and fourth sub-signals are pull-up currents. This pull-up current continues to pull the gate voltage of the first transistor M1 high, causing the first transistor M1 to turn off, and thus the pull-up current unit 1021 continues to stop working. At the same time, this pull-up current continues to pull the gate voltage of the third transistor M3 high, causing the third transistor M3 to conduct and generate current. This current, after being mirrored by the current mirror, continues to output a pull-down current to the output of the error amplifier (i.e., ...). Figure 4 The dashed current flowing out of the DC-DC converter 20 causes the error control signal Vc to continue decreasing. When the output voltage V... OUT When the preset voltage is reached, the second transconductance amplifier gm2 stops outputting the fourth sub-signal, thereby causing the pull-down current unit 1022 to stop outputting the pull-down current; at the same time, the first transconductance amplifier gm1 stops outputting the third sub-signal.

[0088] As can be seen from the above, when the load current of DC-DC converter 20 decreases, and the output voltage V... OUT During the recovery process, the pull-up current unit 1021 remains inactive, while the pull-down current unit 1022 continuously outputs pull-down current; when the output voltage V OUT When the preset voltage is reached, the pull-down current unit 1022 stops outputting pull-down current. However, when the load current of the DC-DC converter 20 increases, and the output voltage V... OUTDuring the recovery process, the pull-down current unit 1022 remains inactive, while the pull-up current unit 1021 continuously outputs pull-up current; when the output voltage V OUT When the preset voltage is reached, the pull-up current unit 1021 stops outputting pull-up current.

[0089] In one embodiment of this application, such as Figure 4 As shown, the coupling module 103 includes a first capacitor C1. The first terminal of the first capacitor C1 is connected to the common terminal of the first feedback resistor and the output capacitor in the DC-DC converter 20. The second terminal of the first capacitor C1 is connected to both the transconductance amplification module 101 and the common terminal of the first feedback resistor and the second feedback resistor in the DC-DC converter 20. Specifically, the first capacitor C1 is used to convert the output voltage V... OUT The changes are rapidly coupled to the transconductance amplification module 101.

[0090] The following is combined Figure 4 To reiterate the working principle of this application.

[0091] When the load current of DC-DC converter 20 increases (i.e., when the load of DC-DC converter 20 suddenly becomes heavier), the output voltage V OUT The voltage will decrease, at which point the first capacitor C1 will decrease according to the reduced output voltage V. OUT The first coupled voltage is output to the non-inverting inputs of the first transconductance amplifier gm1 and the second transconductance amplifier gm2, respectively; this first coupled voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly less than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF Feedback voltage V FB The first sub-signal, i.e., the pull-down current, is output by the first coupling sub-voltage. This pull-down current pulls the gate voltage of the first transistor M1 low, causing the first transistor M1 to conduct and generate current. This current, after being mirrored by the current mirror, outputs a pull-up current (i.e., ...) to the output of the error amplifier. Figure 4 The dashed current flowing into the DC-DC converter 20 shown in the figure enables the error control signal V. C The voltage increases rapidly to adapt to heavier loads. Meanwhile, the second transconductance amplifier gm2 adjusts according to the reference voltage V. REF Feedback voltage V FB The first coupling voltage outputs the second sub-signal, which is the pull-down current. This pull-down current will pull down the gate voltage of the third transistor M3, causing the third transistor M3 to turn off, and thus the pull-down current unit 1022 stops working.

[0092] When the coupling ends, the output voltage V OUTWhen the voltage is less than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always less than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF and feedback voltage V FB The first sub-signal, i.e., the pull-down current, continues to output. This pull-down current will continue to pull the gate voltage of the first transistor M1 low, causing the first transistor M1 to conduct and generate current. This current, after being mirrored by the current mirror, continues to output a pull-up current to the output of the error amplifier (i.e., Figure 4 The dashed current flowing into the DC-DC converter 20 (to make the error control signal V) C Continue to increase; when the output voltage V OUT When the preset voltage is reached, the first transconductance amplifier gm1 stops outputting the first sub-signal, thereby causing the pull-up current unit 1021 to stop outputting the pull-up current. Simultaneously, the second transconductance amplifier gm2 operates according to the reference voltage V. REF and feedback voltage V FB The second sub-signal, i.e., the pull-down current, continues to output. This pull-down current will continue to pull the gate voltage of the third transistor M3 low, causing the third transistor M3 to turn off, and thus the pull-down current unit 1022 will continue to stop working; when the output voltage V OUT When the preset voltage is reached, the second transconductance amplifier gm2 stops outputting the second sub-signal.

[0093] When the load current of DC-DC converter 20 decreases (i.e., when the load of DC-DC converter 20 suddenly becomes lighter), the output voltage V OUT The voltage will rise, at which point the first capacitor C1 will increase according to the increased output voltage V. OUT The second coupler voltage is output to the non-inverting inputs of the first transconductance amplifier gm1 and the second transconductance amplifier gm2, respectively; this second coupler voltage is directly superimposed on the feedback voltage V. FB Above, so that the superimposed feedback voltage V FBD Significantly greater than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF Feedback voltage V FB The second coupling sub-voltage outputs a third sub-signal, namely the pull-up current. This pull-up current pulls the gate voltage of the first transistor M1 high, turning off the first transistor M1, and thus stopping the pull-up current unit 1021 from working. Simultaneously, the second transconductance amplifier gm2 adjusts its output based on the reference voltage V. REF Feedback voltage V FBThe second coupling sub-voltage outputs the fourth sub-signal, i.e., the pull-up current. This pull-up current pulls up the gate voltage of the third transistor M3, causing the third transistor M3 to conduct and generate current. This current, after being mirrored by the current mirror, outputs a pull-down current (i.e., ...) to the output of the error amplifier. Figure 4 The dashed current flowing out of the DC-DC converter 20 causes the error control signal Vc to decrease rapidly, thereby adapting to a lighter load.

[0094] When the coupling ends, the output voltage V OUT When the voltage is greater than the preset voltage, that is, when the output voltage V... OUT During the recovery process, the feedback voltage V FB Always greater than the reference voltage V REF Therefore, the first transconductance amplifier gm1 is based on the reference voltage V. REF and feedback voltage V FB The third sub-signal, i.e., the pull-up current, continues to be output. This pull-up current will continue to pull the gate voltage of the first transistor M1 high, causing the first transistor M1 to turn off, and thus the pull-up current unit 1021 will continue to stop working; when the output voltage V OUT When the preset voltage is reached, the first transconductance amplifier gm1 stops outputting the third sub-signal. Simultaneously, the second transconductance amplifier gm2 operates according to the reference voltage V. REF and feedback voltage V FB The fourth sub-signal, i.e., the pull-up current, continues to be output. This pull-up current will further pull up the gate voltage of the third transistor M3, causing the third transistor M3 to conduct and generate current. This current, after being mirrored by the current mirror, continues to output a pull-down current to the output of the error amplifier (i.e., Figure 4 The dashed current flowing out of the DC-DC converter 20 causes the error control signal Vc to continue to decrease; when the output voltage V... OUT When the preset voltage is reached, the second transconductance amplifier gm2 stops outputting the fourth sub-signal, thereby causing the pull-down current unit 1022 to stop outputting the pull-down current.

[0095] Figure 5 A schematic diagram comparing key waveforms of a boost DC-DC converter with and without the transient response boost circuit 10 is shown. Figure I LOAD I is the load current. L This represents the inductor current. At time t1, the load on the boost DC-DC converter changes from light load to heavy load. The error control signal Vc of the boost DC-DC converter with transient response boost circuit 10 reacts faster, and the output voltage V... OUTWith a smaller undershoot and shorter recovery time, the transient response performance is superior. Similarly, at time t2, the load of the boost DC-DC converter changes from heavy load to light load. The error control signal Vc of the boost DC-DC converter with transient response enhancement circuit 10 responds faster, and the output voltage V... OUT It has a smaller overshoot and shorter recovery time, resulting in superior transient response performance.

[0096] In summary, the transient response enhancement circuit 10 proposed in this application can improve the transient response of the DC-DC converter 20 without affecting loop stability. When the load of the DC-DC converter 20 changes, this circuit outputs current to the output of the error amplifier, causing the error control signal to change rapidly, thereby quickly changing the peak value of the inductor current to adapt to the load change, reduce output voltage fluctuations, and shorten the output stabilization time. The control method of this circuit is simple and efficient, and does not affect the loop bandwidth and stability. It effectively solves the problem in the prior art where increasing bandwidth to improve transient response leads to a decrease in system stability; in particular, it solves the problem in boost-type DC-DC converters where the right half-plane zero point shifts to a lower frequency with the increase of load or duty cycle, thus limiting the loop bandwidth and further deteriorating system stability and transient response.

[0097] This application also provides a DC-DC converter, including the transient response enhancement circuit described above. Since the DC-DC converter provided in this application adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be elaborated further here.

[0098] This application also provides a switching power supply chip, including the DC-DC converter described above. Since the switching power supply chip provided in this application adopts all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be elaborated further here.

[0099] This application also provides an electronic device including the aforementioned switching power supply chip. Since the electronic device provided in this application employs all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be elaborated upon further here. The electronic device provided in this application can be any electronic device containing the aforementioned switching power supply chip.

[0100] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0101] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A transient response enhancement circuit, characterized in that, It includes a transconductance amplification module, a current module, and a coupling module. The transconductance amplification module is connected to the coupling module, the current module, and the common terminal of the first feedback resistor and the second feedback resistor in the DC-DC converter. The current module is connected to the output terminal of the error amplifier in the DC-DC converter. The coupling module is connected to the common terminal of the first feedback resistor and the output capacitor in the DC-DC converter. When the load current of the DC-DC converter changes, the coupling module is used to output a coupling voltage to the transconductance amplification module according to the change in the output voltage of the DC-DC converter; the transconductance amplification module is used to output a first signal according to the reference voltage, the feedback voltage of the DC-DC converter and the coupling voltage; The current module is used to output a first current according to the first signal, so that the error control signal output by the error amplifier changes rapidly; When the coupling ends and the output voltage does not reach the preset voltage, the transconductance amplification module continues to output a first signal based on the reference voltage and the feedback voltage, so that the current module continues to output a first current, thereby causing the error control signal to continue to adjust; when the output voltage reaches the preset voltage, the transconductance amplification module stops outputting the first signal, thereby causing the current module to stop outputting the first current. The transconductance amplification module includes a first transconductance amplification unit and a second transconductance amplification unit. The first transconductance amplification unit is connected to the coupling module, the current module, the second transconductance amplification unit, and the common terminal of the first feedback resistor and the second feedback resistor in the DC-DC converter. The second transconductance amplification unit is connected to the current module. The first signal includes a first sub-signal, a second sub-signal, a third sub-signal, and a fourth sub-signal. The first current includes a pull-up current and a pull-down current. The coupling voltage includes a first coupling sub-voltage and a second coupling sub-voltage. When the load current of the DC-DC converter increases, the coupling module is used to output a first coupling sub-voltage to the first transconductance amplification unit and the second transconductance amplification unit respectively according to the reduced output voltage; the first transconductance amplification unit is used to output a first sub-signal according to the reference voltage, the feedback voltage and the first coupling sub-voltage; The second transconductance amplifier unit is used to output a second sub-signal based on the reference voltage, the feedback voltage, and the first coupling sub-voltage; The current module is used to output a pull-up current according to the first sub-signal and the second sub-signal, so that the error control signal rises rapidly. When the coupling effect ends and the output voltage is less than the preset voltage, the first transconductance amplification unit continues to output a first sub-signal based on the reference voltage and the feedback voltage, and the second transconductance amplification unit continues to output a second sub-signal based on the reference voltage and the feedback voltage, so that the current module continues to output pull-up current, thereby causing the error control signal to continue to rise; when the output voltage reaches the preset voltage, the first transconductance amplification unit stops outputting the first sub-signal, the second transconductance amplification unit stops outputting the second sub-signal, thereby causing the current module to stop outputting pull-up current; When the load current of the DC-DC converter decreases, the coupling module is used to output a second coupling sub-voltage to the first transconductance amplification unit and the second transconductance amplification unit respectively according to the increased output voltage; the first transconductance amplification unit is used to output a third sub-signal according to the reference voltage, the feedback voltage and the second coupling sub-voltage; The second transconductance amplifier unit is used to output a fourth sub-signal based on the reference voltage, the feedback voltage, and the second coupling sub-voltage; The current module is used to output a pull-down current according to the third sub-signal and the fourth sub-signal, so that the error control signal is reduced rapidly; When the coupling ends and the output voltage is greater than the preset voltage, the first transconductance amplification unit is used to continue to output a third sub-signal based on the reference voltage and the feedback voltage, and the second transconductance amplification unit is used to continue to output a fourth sub-signal based on the reference voltage and the feedback voltage, so that the current module continues to output pull-down current, thereby causing the error control signal to continue to decrease. When the output voltage reaches the preset voltage, the first transconductance amplification unit stops outputting the third sub-signal, the second transconductance amplification unit stops outputting the fourth sub-signal, and thus the current module stops outputting the pull-down current. The current module includes a pull-up current unit and a pull-down current unit. The pull-up current unit is connected to the output terminals of the first transconductance amplifier unit, the pull-down current unit, and the error amplifier, respectively. The pull-down current unit is connected to the second transconductance amplifier unit. When the load current of the DC-DC converter increases, the pull-down current unit stops working according to the second sub-signal, and the pull-up current unit outputs a pull-up current according to the first sub-signal to make the error control signal rise rapidly. When the coupling ends and the output voltage is less than a preset voltage, the pull-down current unit still stops working according to the second sub-signal, and the pull-up current unit continues to output a pull-up current according to the first sub-signal to make the error control signal continue to rise. When the output voltage reaches the preset voltage, the first transconductance amplification unit stops outputting the first sub-signal, thereby causing the pull-up current unit to stop outputting the pull-up current. When the load current of the DC-DC converter decreases, the pull-up current unit stops working according to the third sub-signal, and the pull-down current unit outputs pull-down current according to the fourth sub-signal to rapidly reduce the error control signal; when the coupling ends and the output voltage is greater than the preset voltage, the pull-up current unit still stops working according to the third sub-signal, and the pull-down current unit continues to output pull-down current according to the fourth sub-signal to further reduce the error control signal. When the output voltage reaches the preset voltage, the second transconductance amplifier unit stops outputting the fourth sub-signal, thereby causing the pull-down current unit to stop outputting the pull-down current.

2. The transient response enhancement circuit according to claim 1, characterized in that, The first transconductance amplification unit includes a first transconductance amplifier. The non-inverting terminal of the first transconductance amplifier is connected to the common terminal of the first feedback resistor and the second feedback resistor in the coupling module, the second transconductance amplification unit, and the DC-DC converter. The inverting terminal of the first transconductance amplifier is used to receive a reference voltage. The output terminal of the first transconductance amplifier is connected to the current module.

3. The transient response enhancement circuit according to claim 1, characterized in that, The second transconductance amplification unit includes a second transconductance amplifier. The non-inverting terminal of the second transconductance amplifier is connected to the common terminal of the first feedback resistor and the second feedback resistor in the first transconductance amplification unit, the coupling module, and the DC-DC converter, respectively. The inverting terminal of the second transconductance amplifier is used to receive a reference voltage. The output terminal of the second transconductance amplifier is connected to the current module.

4. The transient response enhancement circuit according to claim 1, characterized in that, The pull-up current unit includes a first transistor and a second transistor. The gate of the first transistor is connected to the drain of the first transistor, the gate of the second transistor, and the first transconductance amplification unit, respectively. The source of the first transistor and the source of the second transistor both receive the power supply voltage. The drain of the second transistor is connected to the output terminal of the pull-down current unit and the error amplifier, respectively.

5. The transient response enhancement circuit according to claim 1, characterized in that, The pull-down current unit includes a third transistor and a fourth transistor. The gate of the third transistor is connected to the drain of the third transistor, the gate of the fourth transistor, and the second transconductance amplification unit, respectively. The sources of the third transistor and the fourth transistor are both grounded. The drain of the fourth transistor is connected to the pull-up current unit and the output terminal of the error amplifier, respectively.

6. The transient response enhancement circuit according to claim 1, characterized in that, The coupling module includes a first capacitor, a first terminal of which is connected to the common terminal of the first feedback resistor and the output capacitor in the DC-DC converter, and a second terminal of which is connected to the common terminal of the transconductance amplification module and the first feedback resistor and the second feedback resistor in the DC-DC converter.

7. A DC-DC converter, characterized in that, Includes the transient response enhancement circuit as described in any one of claims 1-6.

Images