WO2017067174A1 - Method and system for enhancing load transient response of voltage-mode buck converter - Google Patents

Method and system for enhancing load transient response of voltage-mode buck converter Download PDF

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Publication number
WO2017067174A1
WO2017067174A1 PCT/CN2016/084276 CN2016084276W WO2017067174A1 WO 2017067174 A1 WO2017067174 A1 WO 2017067174A1 CN 2016084276 W CN2016084276 W CN 2016084276W WO 2017067174 A1 WO2017067174 A1 WO 2017067174A1
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voltage
vout
feedback
vout1
current
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PCT/CN2016/084276
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French (fr)
Chinese (zh)
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耿玮生
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深圳市中兴微电子技术有限公司
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Publication of WO2017067174A1 publication Critical patent/WO2017067174A1/en

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H02M1/0016—Control circuits providing compensation of output voltage deviations using feedforward of disturbance parameters
    • H02M1/0019—Control circuits providing compensation of output voltage deviations using feedforward of disturbance parameters the disturbance parameters being load current fluctuations

Definitions

  • the invention relates to circuit electronic technology, in particular to a load transient response enhancement method and system for a voltage mode buck converter.
  • Buck converters are mainly used in scenarios where the input voltage is relatively high and the output voltage is low.
  • the general-purpose voltage-mode buck converter is mainly composed of an oscillator, a ramp generator, an error amplifier, a compensation network, a pulse width generator, a logic control, a drive and power switch, an output filter, a feedback network, and some protection modules.
  • the oscillator generates a fixed frequency, the synchronous control logic and the power tube switch; the ramp generator generates a ramp signal for pulse width control; the feedback network, the error amplifier and the compensation network form the control core of the converter for varying the output voltage Amplification; the ramp signal and the error amplifier signal are compared by a pulse width generator to generate a pulse width control signal; the pulse width control signal is combined with the oscillator signal to generate a duty cycle through a logic and power switch, and the duty cycle controls the output power tube switch. After filtering the network, a stable voltage is output.
  • the existing buck converter can output a stable voltage, which can meet the application scenario where the load changes little or relatively slowly; when the load changes relatively fast or the latter stage requires high voltage stability, the traditional structure is difficult to meet the design requirements. This requires changing the architecture or adding additional circuitry to enhance load responsiveness.
  • embodiments of the present invention are directed to a load transient response enhancement method and system for a voltage mode buck converter to improve load transient response capability of a voltage mode buck converter.
  • a first aspect of the embodiments of the present invention provides a load transient response enhancement method for a voltage mode buck converter, the method comprising:
  • the amplitude of the fluctuating current Itran is ramped, and the transient response output voltage Vout of the voltage mode buck converter is generated according to the obtained ramp signal.
  • the amplitude of the ripple current Itran is ramped, and the transient response output voltage Vout of the voltage mode buck converter is generated according to the obtained ramp signal, including:
  • the amplitude of the ripple current Itran is ramped to generate a feedback tooth voltage Vramp; and the transient response output voltage Vout of the voltage mode buck converter is modulated according to the pulse width of the feedback tooth voltage Vramp unit period.
  • the method further includes: presetting a first input threshold voltage ⁇ V1 and a second input threshold voltage ⁇ V2;
  • the converting the amplitude waveform of the calculated difference to obtain the ripple current Itran includes:
  • Vout-Vout1 When Vout-Vout1 is greater than ⁇ V1, the amplitude waveform of Vout-Vout1- ⁇ V1 is converted into the ripple current Itran of the corresponding waveform, and the obtained ripple current Itran is a forward current;
  • Vout1-Vout When Vout1-Vout is greater than ⁇ V2, the amplitude waveform of Vout1-Vout- ⁇ V2 is converted into the ripple current Itran of the corresponding waveform, and the obtained ripple current Itran is a reverse current;
  • the generating the feedback tooth voltage Vramp includes:
  • the ripple current Itran is superimposed with a preset reference current Iref to generate a feedback current Iramp, and a feedback tooth voltage Vramp is generated according to the magnitude of the feedback current Iramp.
  • the method further includes: generating a rectangular wave for modulation according to a difference between the feedback tooth voltage Vramp and the feedback voltage Vcomp; wherein the feedback voltage Vcomp passes through the reference voltage Vref and the divided output voltage Vout The difference is amplified, and the portion where the feedback tooth voltage Vramp is greater than the feedback voltage Vcomp is a high level portion of the rectangular wave.
  • the first input threshold voltage ⁇ V1 and the second input threshold voltage ⁇ V2 are sequentially offset voltages of the first voltage comparison operational amplifier and the second voltage comparison operational amplifier; wherein the offset voltage is a preset fixed voltage
  • the offset voltage is generated by the asymmetry of the output stages of the two output MOS transistors of the transconductance operational amplifier of the voltage comparison op amp.
  • a first aspect of the embodiments of the present invention provides a load transient response enhancement system of a voltage mode buck converter, the system including a low pass filter, a voltage comparison operational amplifier, a ramp generator, and a voltage generating device;
  • the low pass filter is configured to low pass filter the output voltage Vout of the voltage mode buck converter to generate an average voltage Vout1;
  • the voltage comparison op amp is configured to calculate a difference between Vout and Vout1, and convert the calculated amplitude waveform of the difference to obtain a ripple current Itran;
  • the ramp generator is configured to ramp the amplitude of the ripple current Itran;
  • the voltage generating device is configured to generate a transient response output voltage Vout of the voltage mode buck converter based on the obtained ramp signal.
  • the voltage comparison operational amplifier includes: a first voltage comparison operational amplifier and a second voltage comparison operational amplifier;
  • the first voltage comparison operational amplifier presets the first input threshold voltage ⁇ V1, the second voltage Comparing the operational amplifier with a second input threshold voltage ⁇ V2;
  • Vout-Vout1- ⁇ V1 When Vout-Vout1- ⁇ V1 is greater than zero, the first voltage is compared with the operational amplifier, and the first voltage comparison op amp outputs the forward ripple current Itran according to the amplitude of Vout-Vout1- ⁇ V1;
  • Vout1-Vout- ⁇ V2 When Vout1-Vout- ⁇ V2 is greater than zero, the second voltage is compared with the operational amplifier, and the second voltage comparison op amp outputs the reverse ripple current Itran according to the magnitude of Vout1-Vout- ⁇ V2.
  • the ramp generator is configured to superimpose the ripple current Itran with a preset reference current Iref to generate a feedback current Iramp, and generate a feedback tooth voltage Vramp according to the magnitude of the feedback current Iramp.
  • the system further includes an error amplifier EA configured to generate a feedback voltage Vcomp according to the reference voltage Vref and the divided output voltage Vout;
  • EA error amplifier
  • the voltage generating device is configured to generate a pulse width signal according to a difference between the feedback tooth voltage Vramp and the feedback voltage Vcomp, and modulate the pulse width signal to generate a transient response output voltage of the voltage mode buck converter. Vout.
  • the system further includes a compensation network compensation, the feedback voltage Vcomp being a voltage compensated by the compensation network compensation.
  • the first voltage comparison op amp and the second voltage comparison op amp both comprise a transconductance operational amplifier and a mirror current circuit;
  • An output stage of the two output MOS transistors of the transconductance operational amplifier is asymmetrically generated with an offset voltage; the first input threshold voltage ⁇ V1 and the second input threshold voltage ⁇ V2 are sequentially a first voltage comparison operational amplifier and a second voltage comparison operation Offset voltage
  • the mirror current circuit is located at an output of the voltage comparison op amp, and the current of the mirror current circuit is unidirectional.
  • the load transient response enhancement method and system of the voltage mode buck converter provided by the embodiment of the present invention performs low-pass filtering on the output voltage Vout of the voltage mode buck converter to generate an average voltage Vout1, and performs a difference between Vout and Vout1. The value is calculated and the amplitude waveform of the calculated difference is calculated.
  • the embodiment of the invention has the advantages of simple structure and fast response, can greatly improve the load transient response capability of the voltage mode buck converter, and can effectively improve the load transient response difference when the voltage mode is stepped down.
  • the problem is that it can effectively improve the accuracy of the output voltage due to load changes.
  • FIG. 1 is a schematic diagram of a processing flow of a load transient response enhancement method of a voltage mode buck converter according to an embodiment of the present invention
  • FIG. 2 is a schematic structural diagram of a load transient response enhancement system of a voltage mode buck converter according to an embodiment of the present invention
  • FIG. 3 is a schematic structural diagram of a first voltage comparison operational amplifier according to an embodiment of the present invention.
  • FIG. 4 is a schematic structural diagram of a second voltage comparison operational amplifier according to an embodiment of the present invention.
  • FIG. 5 is a schematic structural diagram of a ramp generator ramp according to an embodiment of the present invention.
  • FIG. 6 is a schematic diagram of a transient change waveform when a load is decreased according to an embodiment of the present invention
  • FIG. 7 is a schematic diagram of a transient change waveform when a load rises according to an embodiment of the present invention.
  • the output voltage Vout of the voltage mode buck converter is low-pass filtered to generate an average voltage Vout1; the difference between Vout and Vout1 is calculated, and the amplitude waveform of the obtained difference is converted.
  • the ripple current Itran is obtained; the amplitude of the ripple current Itran is ramped, and the transient response output voltage Vout of the voltage mode buck converter is generated according to the obtained ramp signal.
  • the ramp processing generates a transient response output voltage of the voltage mode buck converter Vout includes: firstly ramping the amplitude of the ripple current Itran to generate a feedback tooth voltage Vramp; and modulating the transient response output of the voltage mode buck converter according to the pulse width in the feedback tooth voltage Vramp unit period Voltage Vout.
  • the load transient response enhancement method of the voltage mode buck converter provided by the embodiment of the present invention is as shown in FIG. 1 , and the processing flow of the method includes the following steps:
  • the current conversion of the amplitude waveform of the difference of Vout minus Vout1 can be completed by using the voltage comparison operational amplifier.
  • the voltage comparison op amp first calculates the difference between Vout and Vout1, and converts the calculated amplitude curve into The current curve of the corresponding waveform.
  • the step may include: first ramping the amplitude of the ripple current Itran to generate a feedback tooth voltage Vramp; and modulating the transient response of the voltage mode buck converter according to the pulse width of the feedback tooth voltage Vramp unit period Output voltage Vout.
  • the ramp generator ramp can be used for ramp processing, and the capacitor of the ramp generator ramp is periodically charged by the ripple current Itran to obtain a voltage ramp curve in the unit period; wherein, the forward output current at a certain time is higher. Larger, the slope of the voltage ramp of the capacitor is larger, and conversely, the slope of the voltage ramp of the capacitor is smaller.
  • the pulse width generating device of the voltage generating device can be used to perform rectangular wave processing on the feedback tooth voltage Vramp to obtain a corresponding pulse width; the pulse width is modulated by the logic driving circuit to generate The transient response output voltage Vout of the voltage mode buck converter.
  • the feedback tooth voltage Vramp may be preset with a voltage mode buck converter or according to a base value fed back by the output voltage Vout, and a portion of the Vramp greater than the base value is a high level of the rectangular wave, thereby obtaining a corresponding pulse. Wide, modulating the pulse width to generate a transient response output voltage Vout.
  • the first input threshold voltage ⁇ V1 and the second input threshold voltage ⁇ V2 may be preset; correspondingly, the amplitude waveform of the calculated difference is converted to obtain a ripple current Itran ,include:
  • Vout-Vout1 When Vout-Vout1 is greater than ⁇ V1, the amplitude waveform of Vout-Vout1- ⁇ V1 is converted into the ripple current Itran of the corresponding waveform, and the obtained ripple current Itran is a forward current;
  • Vout1-Vout When Vout1-Vout is greater than ⁇ V2, the amplitude waveform of Vout1-Vout- ⁇ V2 is converted into the ripple current Itran of the corresponding waveform, and the obtained ripple current Itran is a reverse current;
  • the first input threshold voltage ⁇ V1 and the second input threshold voltage ⁇ V2 are offset voltages of the first voltage comparison operational amplifier and the second voltage comparison operational amplifier, respectively, wherein the offset voltage is a preset fixed value, and the voltage comparison is performed.
  • the output stage of the two output MOS transistors of the op amp's transconductance operational amplifier is asymmetrically generated to generate the offset voltage.
  • the ripple current Itran is a mirror current capable of driving other devices.
  • the ripple current Itran is superimposed with a preset reference current Iref to generate a feedback current Iramp, and a feedback tooth voltage Vramp is generated according to the magnitude of the feedback current Iramp.
  • a rectangular wave for modulation may be generated according to a difference between the feedback tooth voltage Vramp and the feedback voltage Vcomp (ie, a base value preset by the voltage mode buck converter), thereby adjusting the output duty ratio.
  • the feedback voltage Vcomp is obtained by amplifying the difference between the reference voltage Vref and the stepped output voltage Vout, and the portion of the feedback tooth voltage Vramp greater than the feedback voltage Vcomp is a high level portion of the rectangular wave; the feedback voltage Vcomp For a compensated voltage, the compensation voltage can be made The waveform of the feedback voltage Vcomp is more gradual.
  • the system includes: a low pass filter, a voltage comparison operational amplifier, a ramp generator ramp, and a voltage generating device; among them,
  • the low pass filter comprising C11 and R11, for low pass filtering the output voltage Vout of the voltage mode buck converter to generate an average voltage Vout1;
  • the voltage comparison op amp is configured to calculate a difference between Vout and Vout1, and convert the calculated amplitude waveform of the difference to obtain a ripple current Itran;
  • the ramp generator is configured to ramp the amplitude of the ripple current Itran;
  • the voltage generating device is configured to generate a transient response output voltage Vout of the voltage mode buck converter based on the obtained ramp signal.
  • the ramp generator ramps the amplitude of the ripple current Itran to generate a feedback dentate voltage Vramp;
  • the voltage generating device is configured to generate a pulse width signal according to a difference between the feedback tooth voltage Vramp and the feedback voltage Vcomp, and modulate the pulse width signal to generate a transient response output voltage of the voltage mode buck converter. Vout;
  • the voltage generating device may further include a pulse width generating device PWM and a logic driving circuit (Logic+Driver), and the pulse width generating device performs a rectangular wave processing on the feedback tooth voltage Vramp according to the feedback tooth voltage Vramp and the feedback.
  • the difference of the voltage Vcomp is obtained by the corresponding pulse width; the pulse width obtained by the logic driving circuit is modulated to generate a transient response output voltage Vout of the voltage mode buck converter.
  • the voltage comparison operational amplifier includes a first voltage comparison operational amplifier gm1 and a second voltage comparison operational amplifier gm2, the specific structure is referred to FIG. 3 and FIG. 4; and the first voltage comparison operational amplifier gm1 presets the first input threshold voltage ⁇ V1, The second voltage comparison op amp gm2 presets the second input threshold voltage ⁇ V2;
  • the voltage comparison op amp converts the amplitude waveform of the calculated difference To the wave current Itran, specifically includes:
  • Vout-Vout1- ⁇ V1 When Vout-Vout1- ⁇ V1 is greater than 0, the first voltage is compared with the operational amplifier, and the first voltage comparison op amp outputs the forward ripple current Itran according to the amplitude of Vout-Vout1- ⁇ V1, that is, the current flows out of the first voltage comparison op amp The direction is positive;
  • Vout1-Vout- ⁇ V2 When Vout1-Vout- ⁇ V2 is greater than 0, the second voltage is compared with the operational amplifier, and the second voltage comparison op amp outputs the reverse ripple current Itran according to the amplitude of Vout1-Vout- ⁇ V2, that is, the current flows into the second voltage comparison op amp The direction is reverse.
  • the first voltage comparison op amp gm1 and the second voltage comparison op amp gm2 each include a transconductance operational amplifier and a mirror current circuit, and an output stage of the two output MOS transistors of the transconductance operational amplifier generates an offset voltage asymmetrically;
  • the first input threshold voltage ⁇ V1 and the second input threshold voltage ⁇ V2 are sequentially the offset voltages of the first voltage comparison operational amplifier and the second voltage comparison operational amplifier;
  • the mirror current circuit is located at the output end of the voltage comparison operational amplifier, and The current in the mirror current circuit is unidirectional.
  • the ripple current Itran is a mirror current capable of driving other devices.
  • the structure of the first voltage comparison op amp gm1 is as shown in FIG. 3.
  • Vout-Vout1 When the Vout transient change value (Vout-Vout1) is less than ⁇ V1, gm1 is in a large signal operation state. Since the MOS tube output stage M18 near the VIN terminal is higher than M16, the voltage output point Vgm1 is VIN, and the output ripple current Itran is outputted.
  • Vout transient change value (Vout-Vout1) is greater than ⁇ V1, that is, when Vout instantaneously becomes high, the value of Vout-Vout1 is larger, the voltage of the voltage output point Vgm1 is lowered, and the voltage difference between VIN and Vgm1 is such that M19 and M10 Turned on, so that the first voltage comparison op amp gm1 is in an amplified state.
  • M19 and M10 form a mirror current circuit.
  • the amplitude of the output voltage Vgm1 controls the current of M19.
  • the larger the input voltage difference (Vout-Vout1) the lower the amplitude of the output voltage Vgm1 and the larger the output current (Itran).
  • the number of MOS transistors of the M11 and M12 portions of the input stage may be mismatched, thereby generating the offset voltage ⁇ V1.
  • the first A voltage comparison op amp gm1 can only work if Vout-Vout1 is greater than ⁇ V1. If it is less than ⁇ V1, the MOS transistor of the mirror current circuit is in a reverse-off state.
  • the structure of the second voltage comparison op amp gm2 is similar.
  • the structure is similar to the structure of the first voltage comparison op amp.
  • Vout transient change difference Vout1-Vout
  • gm2 is in a large signal operation state. Since the MOS tube output stage M26 close to the ground terminal is higher than M28, the voltage output point Vgm2 is GND, and the output fluctuation occurs.
  • the current Itran 0; when the Vout transient change value (Vout1-Vout) is greater than ⁇ V2, that is, when Vout instantaneously becomes lower, the value of Vout1-Vout is larger, the voltage of the voltage output point Vgm2 is increased, and the voltage of Vgm2 and the ground is higher.
  • the difference causes M29 and M20 to be turned on, so that the second voltage is compared with the op amp gm2 in an amplified state.
  • M19 and M10 form a mirror current circuit.
  • the amplitude of the output voltage Vgm2 controls the current of M19.
  • the larger the input voltage difference (Vout1-Vout) the higher the amplitude of the output voltage Vgm2, and the larger the output current (Itran).
  • the number of MOS transistors of the two parts of the input stage M21 and M22 may be mismatched, thereby generating the offset voltage ⁇ V2.
  • the second voltage comparison op amp gm2 can only work if Vout1-Vout is greater than ⁇ V2. If less than ⁇ V2, the MOS transistor of the mirror current circuit is in the reverse-off state.
  • the ramp generator ramp generates a ramp signal by charging and discharging C1 and C2, respectively.
  • the duty ratio of the Clk1 clock of the embodiment of the present invention is 50%, which is obtained by dividing the clk clock by 2.
  • the ramp generator ramp first superimposes the wave current Itran with a preset reference current Iref to generate a feedback current Iramp, and then according to The magnitude of the feedback current Iramp generates a feedback tooth voltage Vramp.
  • the system further includes an error amplifier (EA), and the reference voltage Vref and the stepped output voltage Vout generate a feedback voltage Vcomp through the error amplifier; correspondingly, the pulse width generating device according to the feedback tooth voltage Vramp and the feedback voltage Vcomp The difference value generates a rectangular wave for modulation, and the portion where the feedback tooth voltage Vramp is larger than the feedback voltage Vcomp is a high level portion of the PWM.
  • EA error amplifier
  • the system also includes a compensation network compensation, the feedback voltage Vcomp being a voltage compensated by the compensation network compensation such that the feedback voltage Vcomp forms a gradual waveform.
  • the reference current Iref and the ripple current Itran are superimposed to generate a feedback current Iramp, and the feedback current Iramp current is increased.
  • the forward direction is the direction in which the current increases, which is equivalent to the current.
  • the feedback tooth voltage Vramp ramp signal slope becomes larger, the feedback tooth voltage Vramp is compared with the feedback voltage Vcomp to form a PWM wave. Since the slope of the feedback tooth voltage Vramp is large, the PWM pulse width of the output changes. Large, thus controlling hd and ld causes the duty cycle SW to become smaller, the inductor current IL drops rapidly, and Vout drops, thereby achieving the purpose of rapidly adjusting the output voltage Vout.
  • the reference current Iref and the ripple current Itran are superimposed to generate a feedback current Iramp, and the feedback current Iramp current is decreased.
  • the negative direction is the direction in which the current decreases, which is equivalent to the current.
  • the reference current Iref is extracted to reduce the reference current; at the same time, the generated feedback tooth voltage Vramp ramp signal slope is decreased; the feedback tooth voltage Vramp is compared with the feedback voltage Vcomp to form a PWM wave due to the feedback tooth voltage Vramp
  • the slope of the PWM wave is small, and the PWM pulse width of the output becomes smaller, so that the control of hd and ld causes the duty ratio SW to become smaller, the inductor current IL rises rapidly, and Vout rises, thereby achieving the purpose of rapidly adjusting the output voltage Vout.
  • the load transient response enhancement method and system for the voltage mode buck converter are low-pass filtered by the output voltage Vout of the voltage mode buck converter to generate an average
  • the voltage Vout1 calculates the difference between Vout and Vout1, and converts the amplitude waveform of the calculated difference into a fluctuating current; and then slopes the amplitude of the fluctuating current to generate a voltage mode buck according to the obtained ramp signal.
  • the converter's transient response output voltage, Vout improves the load transient response of the voltage-mode buck converter and is convenient for industrial production and fabrication.

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  • Dc-Dc Converters (AREA)

Abstract

A method for enhancing load transient response of a voltage-mode buck converter, comprising: performing low-pass filtering of an output voltage Vout of the voltage-mode buck converter to generate an average voltage Vout1 (S1); calculating a difference between Vout and Vout1, and converting the amplitude waveform of the calculated difference into a fluctuating current Itran (S2); ramping the amplitude of the fluctuating current Itran, and generating, according to the obtained ramp signal, a transient response output voltage Vout of the voltage-mode buck converter (S3). Meanwhile, a system for enhancing load transient response of the voltage-mode buck converter is also disclosed.

Description

电压模降压转换器的负载瞬态响应增强方法及系统Load transient response enhancement method and system for voltage mode buck converter 技术领域Technical field
本发明涉及电路电子技术，尤其涉及一种电压模降压转换器的负载瞬态响应增强方法及系统。The invention relates to circuit electronic technology, in particular to a load transient response enhancement method and system for a voltage mode buck converter.
背景技术Background technique
随着各类电子产品市场的迅速发展，能够为电子产品提供稳定电压的电源芯片技术也在不断进步。电源芯片的负载多种多样，负载大小变化不可避免，负载瞬态响应时间和能力已经成为衡量电源芯片优良的关键技术指标。为了保证电源芯片输出电压的精度范围，需要电源芯片具有良好的负载瞬态响应能力。With the rapid development of various electronic product markets, power chip technology capable of providing stable voltage for electronic products is also progressing. The load of the power chip is various, the load size change is unavoidable, and the load transient response time and capability have become the key technical indicators for measuring the excellent power chip. In order to ensure the accuracy range of the output voltage of the power chip, the power chip needs to have good load transient response capability.
降压转换器主要用于输入电压比较高，而输出电压比较低的场景。通用的电压模降压转换器主要由振荡器、斜坡发生器、误差放大器、补偿网络、脉宽发生器、逻辑控制、驱动及功率开关、输出滤波、反馈网络以及一些保护模块组成。由振荡器产生固定频率，同步控制逻辑部分和功率管开关；斜坡发生器产生用于脉宽控制的斜坡信号；反馈网络、误差放大器和补偿网络组成转换器的控制核心，用来将输出电压变化放大；斜坡信号和误差放大器信号经过脉宽发生器比较，产生脉宽控制信号；脉宽控制信号结合振荡器信号通过逻辑及功率开关，产生占空比，占空比控制输出功率管开关，经过滤波网络后，输出稳定电压。Buck converters are mainly used in scenarios where the input voltage is relatively high and the output voltage is low. The general-purpose voltage-mode buck converter is mainly composed of an oscillator, a ramp generator, an error amplifier, a compensation network, a pulse width generator, a logic control, a drive and power switch, an output filter, a feedback network, and some protection modules. The oscillator generates a fixed frequency, the synchronous control logic and the power tube switch; the ramp generator generates a ramp signal for pulse width control; the feedback network, the error amplifier and the compensation network form the control core of the converter for varying the output voltage Amplification; the ramp signal and the error amplifier signal are compared by a pulse width generator to generate a pulse width control signal; the pulse width control signal is combined with the oscillator signal to generate a duty cycle through a logic and power switch, and the duty cycle controls the output power tube switch. After filtering the network, a stable voltage is output.
现有的降压转换器能够输出稳定电压，可以满足负载变化不大或者比较慢的应用场景；对于负载变化比较快或者后级对电压稳定度要求很高时，传统结构很难满足设计要求，这就需要改变架构或者增加额外的电路来增强负载响应能力。 The existing buck converter can output a stable voltage, which can meet the application scenario where the load changes little or relatively slowly; when the load changes relatively fast or the latter stage requires high voltage stability, the traditional structure is difficult to meet the design requirements. This requires changing the architecture or adding additional circuitry to enhance load responsiveness.
发明内容Summary of the invention
有鉴于此，本发明实施例期望提供一种电压模降压转换器的负载瞬态响应增强方法及系统，以提升电压模降压转换器的负载瞬态响应能力。In view of this, embodiments of the present invention are directed to a load transient response enhancement method and system for a voltage mode buck converter to improve load transient response capability of a voltage mode buck converter.
本发明实施例的技术方案是这样实现的：The technical solution of the embodiment of the present invention is implemented as follows:
本发明实施例第一方面提供一种电压模降压转换器的负载瞬态响应增强方法，所述方法包括：A first aspect of the embodiments of the present invention provides a load transient response enhancement method for a voltage mode buck converter, the method comprising:
对电压模降压转换器的输出电压Vout进行低通滤波，产生平均电压Vout1；Low-pass filtering the output voltage Vout of the voltage mode buck converter to generate an average voltage Vout1;
计算Vout与Vout1的差值，并将计算得到的差值的幅值波形进行转换得到波动电流Itran；Calculating the difference between Vout and Vout1, and converting the amplitude waveform of the calculated difference to obtain a ripple current Itran;
对波动电流Itran的幅值进行斜坡处理，根据得到的斜坡信号生成电压模降压转换器的瞬态响应输出电压Vout。The amplitude of the fluctuating current Itran is ramped, and the transient response output voltage Vout of the voltage mode buck converter is generated according to the obtained ramp signal.
可选地，对波动电流Itran的幅值进行斜坡处理，根据得到的斜坡信号生成电压模降压转换器的瞬态响应输出电压Vout，包括：Optionally, the amplitude of the ripple current Itran is ramped, and the transient response output voltage Vout of the voltage mode buck converter is generated according to the obtained ramp signal, including:
先对波动电流Itran的幅值进行斜坡处理，生成反馈齿状电压Vramp；再根据反馈齿状电压Vramp单位周期内的脉宽，调制生成电压模降压转换器的瞬态响应输出电压Vout。First, the amplitude of the ripple current Itran is ramped to generate a feedback tooth voltage Vramp; and the transient response output voltage Vout of the voltage mode buck converter is modulated according to the pulse width of the feedback tooth voltage Vramp unit period.
可选地，所述方法还包括：预先设定第一输入阈值电压ΔV1和第二输入阈值电压ΔV2；Optionally, the method further includes: presetting a first input threshold voltage ΔV1 and a second input threshold voltage ΔV2;
所述将计算得到的差值的幅值波形进行转换得到波动电流Itran，包括：The converting the amplitude waveform of the calculated difference to obtain the ripple current Itran includes:
当Vout-Vout1大于ΔV1时，将Vout-Vout1-ΔV1的幅值波形转换为相应波形的波动电流Itran，所述得到的波动电流Itran为正向电流；When Vout-Vout1 is greater than ΔV1, the amplitude waveform of Vout-Vout1-ΔV1 is converted into the ripple current Itran of the corresponding waveform, and the obtained ripple current Itran is a forward current;
当Vout-Vout1的差值大于零且小于ΔV1时，不产生波动电流Itran；When the difference of Vout-Vout1 is greater than zero and less than ΔV1, no fluctuating current Itran is generated;
当Vout1-Vout大于ΔV2时，将Vout1-Vout-ΔV2的幅值波形转换为相应波形的波动电流Itran，所述得到的波动电流Itran为反向电流； When Vout1-Vout is greater than ΔV2, the amplitude waveform of Vout1-Vout-ΔV2 is converted into the ripple current Itran of the corresponding waveform, and the obtained ripple current Itran is a reverse current;
当Vout1-Vout的差值大于零且小于ΔV2时，不产生波动电流Itran。When the difference between Vout1 - Vout is greater than zero and less than ΔV2, the ripple current Itran is not generated.
可选地，所述生成反馈齿状电压Vramp包括：Optionally, the generating the feedback tooth voltage Vramp includes:
将所述波动电流Itran与预先设定的基准电流Iref叠加生成反馈电流Iramp，根据反馈电流Iramp的幅值生成反馈齿状电压Vramp。The ripple current Itran is superimposed with a preset reference current Iref to generate a feedback current Iramp, and a feedback tooth voltage Vramp is generated according to the magnitude of the feedback current Iramp.
可选地，所述方法还包括：根据反馈齿状电压Vramp与反馈电压Vcomp的差值生成用于调制的矩形波；其中，反馈电压Vcomp通过对基准电压Vref与经过分压的输出电压Vout的差值进行放大得到，反馈齿状电压Vramp大于反馈电压Vcomp的部分为矩形波的高电平部分。Optionally, the method further includes: generating a rectangular wave for modulation according to a difference between the feedback tooth voltage Vramp and the feedback voltage Vcomp; wherein the feedback voltage Vcomp passes through the reference voltage Vref and the divided output voltage Vout The difference is amplified, and the portion where the feedback tooth voltage Vramp is greater than the feedback voltage Vcomp is a high level portion of the rectangular wave.
可选地，所述第一输入阈值电压ΔV1和第二输入阈值电压ΔV2依次为第一电压比较运放和第二电压比较运放的失调电压；其中，所述失调电压为预先设定的固定值，所述失调电压由电压比较运放的跨导运算放大器的两个输出MOS管的输出级不对称产生。Optionally, the first input threshold voltage ΔV1 and the second input threshold voltage ΔV2 are sequentially offset voltages of the first voltage comparison operational amplifier and the second voltage comparison operational amplifier; wherein the offset voltage is a preset fixed voltage The offset voltage is generated by the asymmetry of the output stages of the two output MOS transistors of the transconductance operational amplifier of the voltage comparison op amp.
本发明实施例第一方面提供一种电压模降压转换器的负载瞬态响应增强系统，所述系统包括低通滤波器、电压比较运放、斜坡发生器和电压生成装置；其中，A first aspect of the embodiments of the present invention provides a load transient response enhancement system of a voltage mode buck converter, the system including a low pass filter, a voltage comparison operational amplifier, a ramp generator, and a voltage generating device;
所述低通滤波器，配置为对电压模降压转换器的输出电压Vout进行低通滤波，产生平均电压Vout1；The low pass filter is configured to low pass filter the output voltage Vout of the voltage mode buck converter to generate an average voltage Vout1;
所述电压比较运放，配置为计算Vout与Vout1的差值，并将计算得到的差值的幅值波形进行转换得到波动电流Itran；The voltage comparison op amp is configured to calculate a difference between Vout and Vout1, and convert the calculated amplitude waveform of the difference to obtain a ripple current Itran;
所述斜坡发生器，配置为对波动电流Itran的幅值进行斜坡处理；The ramp generator is configured to ramp the amplitude of the ripple current Itran;
所述电压生成装置，配置为根据得到的斜坡信号生成电压模降压转换器的瞬态响应输出电压Vout。The voltage generating device is configured to generate a transient response output voltage Vout of the voltage mode buck converter based on the obtained ramp signal.
可选地，所述电压比较运放包括：第一电压比较运放和第二电压比较运放；Optionally, the voltage comparison operational amplifier includes: a first voltage comparison operational amplifier and a second voltage comparison operational amplifier;
其中，第一电压比较运放预先设定第一输入阈值电压ΔV1，第二电压 比较运放预先设定第二输入阈值电压ΔV2；Wherein, the first voltage comparison operational amplifier presets the first input threshold voltage ΔV1, the second voltage Comparing the operational amplifier with a second input threshold voltage ΔV2;
当Vout-Vout1-ΔV1大于零时，第一电压比较运放工作，第一电压比较运放根据Vout-Vout1-ΔV1的幅值输出正向波动电流Itran；When Vout-Vout1-ΔV1 is greater than zero, the first voltage is compared with the operational amplifier, and the first voltage comparison op amp outputs the forward ripple current Itran according to the amplitude of Vout-Vout1-ΔV1;
当Vout1-Vout-ΔV2大于零时，第二电压比较运放工作，第二电压比较运放根据Vout1-Vout-ΔV2的幅值输出反向波动电流Itran。When Vout1-Vout-ΔV2 is greater than zero, the second voltage is compared with the operational amplifier, and the second voltage comparison op amp outputs the reverse ripple current Itran according to the magnitude of Vout1-Vout-ΔV2.
可选地，所述斜坡发生器，配置为将所述波动电流Itran与预先设定的基准电流Iref叠加生成反馈电流Iramp，根据反馈电流Iramp的幅值生成反馈齿状电压Vramp。Optionally, the ramp generator is configured to superimpose the ripple current Itran with a preset reference current Iref to generate a feedback current Iramp, and generate a feedback tooth voltage Vramp according to the magnitude of the feedback current Iramp.
可选地，所述系统还包括误差放大器EA，配置为根据基准电压Vref与经过分压的输出电压Vout生成反馈电压Vcomp；Optionally, the system further includes an error amplifier EA configured to generate a feedback voltage Vcomp according to the reference voltage Vref and the divided output voltage Vout;
相应的，所述电压生成装置，配置为根据反馈齿状电压Vramp与反馈电压Vcomp的差值生成脉宽信号，对所述脉宽信号进行调制生成电压模降压转换器的瞬态响应输出电压Vout。Correspondingly, the voltage generating device is configured to generate a pulse width signal according to a difference between the feedback tooth voltage Vramp and the feedback voltage Vcomp, and modulate the pulse width signal to generate a transient response output voltage of the voltage mode buck converter. Vout.
可选地，所述系统还包括补偿网络compensation，所述反馈电压Vcomp为经过补偿网络compensation补偿的电压。Optionally, the system further includes a compensation network compensation, the feedback voltage Vcomp being a voltage compensated by the compensation network compensation.
可选地，所述第一电压比较运放和第二电压比较运放均包括跨导运算放大器和镜像电流电路；Optionally, the first voltage comparison op amp and the second voltage comparison op amp both comprise a transconductance operational amplifier and a mirror current circuit;
所述跨导运算放大器的两个输出MOS管的输出级不对称产生失调电压；所述第一输入阈值电压ΔV1和第二输入阈值电压ΔV2依次为第一电压比较运放和第二电压比较运放的失调电压；An output stage of the two output MOS transistors of the transconductance operational amplifier is asymmetrically generated with an offset voltage; the first input threshold voltage ΔV1 and the second input threshold voltage ΔV2 are sequentially a first voltage comparison operational amplifier and a second voltage comparison operation Offset voltage
所述镜像电流电路位于电压比较运放的输出端，且所述镜像电流电路的电流为单方向。The mirror current circuit is located at an output of the voltage comparison op amp, and the current of the mirror current circuit is unidirectional.
本发明实施例提供的电压模降压转换器的负载瞬态响应增强方法及系统，通过对电压模降压转换器的输出电压Vout进行低通滤波，产生平均电压Vout1，对Vout和Vout1进行差值计算，并将计算得到的差值的幅值波形 转换为波动电流；再通过对波动电流的幅值进行斜坡处理，根据得到的斜坡信号生成电压模降压转换器的瞬态响应输出电压Vout，以实现对电压模降压转换器的输出电压Vout值的实时反馈调节；本发明实施例实现结构简单、响应快速，能使电压模降压转换器的负载瞬态响应能力大大提高，并能有效地改善电压模降压时负载瞬态响应差的问题，且能有效改善由于负载变化所造成的输出电压的精度问题。The load transient response enhancement method and system of the voltage mode buck converter provided by the embodiment of the present invention performs low-pass filtering on the output voltage Vout of the voltage mode buck converter to generate an average voltage Vout1, and performs a difference between Vout and Vout1. The value is calculated and the amplitude waveform of the calculated difference is calculated. Converting to a fluctuating current; then ramping the amplitude of the fluctuating current to generate a transient response output voltage Vout of the voltage-mode buck converter according to the obtained ramp signal to realize an output voltage Vout of the voltage-mode buck converter The real-time feedback adjustment of the value; the embodiment of the invention has the advantages of simple structure and fast response, can greatly improve the load transient response capability of the voltage mode buck converter, and can effectively improve the load transient response difference when the voltage mode is stepped down. The problem is that it can effectively improve the accuracy of the output voltage due to load changes.
附图说明DRAWINGS
图1为本发明实施例提供的电压模降压转换器的负载瞬态响应增强方法的处理流程示意图；1 is a schematic diagram of a processing flow of a load transient response enhancement method of a voltage mode buck converter according to an embodiment of the present invention;
图2为本发明实施例提供的电压模降压转换器的负载瞬态响应增强系统的组成结构示意图；2 is a schematic structural diagram of a load transient response enhancement system of a voltage mode buck converter according to an embodiment of the present invention;
图3为本发明实施例提供的第一电压比较运放的结构示意图；3 is a schematic structural diagram of a first voltage comparison operational amplifier according to an embodiment of the present invention;
图4为本发明实施例提供的第二电压比较运放的结构示意图；4 is a schematic structural diagram of a second voltage comparison operational amplifier according to an embodiment of the present invention;
图5为本发明实施例提供的斜坡发生器ramp的结构示意图；FIG. 5 is a schematic structural diagram of a ramp generator ramp according to an embodiment of the present invention;
图6为本发明实施例提供的负载下降时的瞬态变化波形示意图；6 is a schematic diagram of a transient change waveform when a load is decreased according to an embodiment of the present invention;
图7为本发明实施例提供的负载上升时的瞬态变化波形示意图。FIG. 7 is a schematic diagram of a transient change waveform when a load rises according to an embodiment of the present invention.
具体实施方式detailed description
在本发明实施例中，对电压模降压转换器的输出电压Vout经低通滤波后，产生平均电压Vout1；对Vout与Vout1进行差值计算，并将得到的差值的幅值波形进行转换得到波动电流Itran；对波动电流Itran的幅值进行斜坡处理，根据得到的斜坡信号生成电压模降压转换器的瞬态响应输出电压Vout。In the embodiment of the present invention, the output voltage Vout of the voltage mode buck converter is low-pass filtered to generate an average voltage Vout1; the difference between Vout and Vout1 is calculated, and the amplitude waveform of the obtained difference is converted. The ripple current Itran is obtained; the amplitude of the ripple current Itran is ramped, and the transient response output voltage Vout of the voltage mode buck converter is generated according to the obtained ramp signal.
这里，所述进行斜坡处理生成电压模降压转换器的瞬态响应输出电压 Vout，包括：先对波动电流Itran的幅值进行斜坡处理，生成反馈齿状电压Vramp；再根据反馈齿状电压Vramp单位周期内的脉宽，调制生成电压模降压转换器的瞬态响应输出电压Vout。Here, the ramp processing generates a transient response output voltage of the voltage mode buck converter Vout includes: firstly ramping the amplitude of the ripple current Itran to generate a feedback tooth voltage Vramp; and modulating the transient response output of the voltage mode buck converter according to the pulse width in the feedback tooth voltage Vramp unit period Voltage Vout.
下面结合附图和实施例对本发明作进一步的详细说明；应当理解，以下所说明的优选实施例仅用于说明和解释本发明，并不用于限定本发明。The present invention will be further described in detail with reference to the accompanying drawings and embodiments.
本发明实施例提供的一种电压模降压转换器的负载瞬态响应增强方法，如图1所示，该方法的处理流程包括以下步骤：The load transient response enhancement method of the voltage mode buck converter provided by the embodiment of the present invention is as shown in FIG. 1 , and the processing flow of the method includes the following steps:
S1：将电压模降压转换器的输出电压Vout进行低通滤波(低通滤波为R11和C11)，产生平均电压Vout1；S1: low-pass filtering (low-pass filtering to R11 and C11) of the output voltage Vout of the voltage mode buck converter, generating an average voltage Vout1;
S2：计算Vout与Vout1的差值，并将计算得到的差值的幅值波形进行转换，得到波动电流Itran；S2: calculating a difference between Vout and Vout1, and converting the amplitude waveform of the calculated difference to obtain a ripple current Itran;
这里，可以采用电压比较运放完成对Vout减Vout1的差值的幅值波形的电流转换，例如：电压比较运放先对Vout和Vout1进行差值计算，并将计算得到的幅值曲线转换为相应波形的电流曲线。Here, the current conversion of the amplitude waveform of the difference of Vout minus Vout1 can be completed by using the voltage comparison operational amplifier. For example, the voltage comparison op amp first calculates the difference between Vout and Vout1, and converts the calculated amplitude curve into The current curve of the corresponding waveform.
S3：对波动电流Itran的幅值进行斜坡处理，根据得到的斜坡信号生成电压模降压转换器的瞬态响应输出电压Vout；S3: ramping the amplitude of the ripple current Itran, and generating a transient response output voltage Vout of the voltage mode buck converter according to the obtained ramp signal;
本步骤可包括：先对波动电流Itran的幅值进行斜坡处理，生成反馈齿状电压Vramp；再根据反馈齿状电压Vramp单位周期内的脉宽，调制生成电压模降压转换器的瞬态响应输出电压Vout。The step may include: first ramping the amplitude of the ripple current Itran to generate a feedback tooth voltage Vramp; and modulating the transient response of the voltage mode buck converter according to the pulse width of the feedback tooth voltage Vramp unit period Output voltage Vout.
这里，可以采用斜坡发生器ramp进行斜坡处理，通过波动电流Itran周期性地对斜坡发生器ramp的电容器进行充电，得到在该单位周期内的电压斜坡曲线；其中，某时刻的正向输出电流越大，电容器的电压斜坡的斜率越大，反之，电容器的电压斜坡的斜率越小。Here, the ramp generator ramp can be used for ramp processing, and the capacitor of the ramp generator ramp is periodically charged by the ripple current Itran to obtain a voltage ramp curve in the unit period; wherein, the forward output current at a certain time is higher. Larger, the slope of the voltage ramp of the capacitor is larger, and conversely, the slope of the voltage ramp of the capacitor is smaller.
同时，可采用电压生成装置的脉宽发生装置对反馈齿状电压Vramp进行矩形波化处理，得到相应脉宽；通过逻辑驱动电路对脉宽进行调制生成 电压模降压转换器的瞬态响应输出电压Vout。例如，可以将反馈齿状电压Vramp与电压模降压转换器预先设定的或根据输出电压Vout反馈的基值进行比较，Vramp大于基值的部分为矩形波的高电平，从而得到相应脉宽，对脉宽进行调制生成瞬态响应输出电压Vout。At the same time, the pulse width generating device of the voltage generating device can be used to perform rectangular wave processing on the feedback tooth voltage Vramp to obtain a corresponding pulse width; the pulse width is modulated by the logic driving circuit to generate The transient response output voltage Vout of the voltage mode buck converter. For example, the feedback tooth voltage Vramp may be preset with a voltage mode buck converter or according to a base value fed back by the output voltage Vout, and a portion of the Vramp greater than the base value is a high level of the rectangular wave, thereby obtaining a corresponding pulse. Wide, modulating the pulse width to generate a transient response output voltage Vout.
为进一步更精确地得到输出波动电流Itran，可预先设定第一输入阈值电压ΔV1和第二输入阈值电压ΔV2；相应的，所述将计算得到的差值的幅值波形进行转换得到波动电流Itran，包括：To further obtain the output ripple current Itran more accurately, the first input threshold voltage ΔV1 and the second input threshold voltage ΔV2 may be preset; correspondingly, the amplitude waveform of the calculated difference is converted to obtain a ripple current Itran ,include:
当Vout-Vout1大于ΔV1时，将Vout-Vout1-ΔV1的幅值波形转换为相应波形的波动电流Itran，所述得到的波动电流Itran为正向电流；When Vout-Vout1 is greater than ΔV1, the amplitude waveform of Vout-Vout1-ΔV1 is converted into the ripple current Itran of the corresponding waveform, and the obtained ripple current Itran is a forward current;
当Vout-Vout1的差值大于零但小于ΔV1时，不产生波动电流Itran；When the difference of Vout-Vout1 is greater than zero but less than ΔV1, no fluctuating current Itran is generated;
当Vout1-Vout大于ΔV2时，将Vout1-Vout-ΔV2的幅值波形转换为相应波形的波动电流Itran，所述得到的波动电流Itran为反向电流；When Vout1-Vout is greater than ΔV2, the amplitude waveform of Vout1-Vout-ΔV2 is converted into the ripple current Itran of the corresponding waveform, and the obtained ripple current Itran is a reverse current;
当Vout1-Vout的差值大于零但小于ΔV2时，不产生波动电流Itran。When the difference of Vout1-Vout is greater than zero but less than ΔV2, the ripple current Itran is not generated.
这里，所述第一输入阈值电压ΔV1和第二输入阈值电压ΔV2分别为第一电压比较运放和第二电压比较运放的失调电压，其中，失调电压为预先设定的固定值，电压比较运放的跨导运算放大器的两个输出MOS管的输出级不对称产生所述失调电压。其中，波动电流Itran为能够驱动其它设备的镜像电流。Here, the first input threshold voltage ΔV1 and the second input threshold voltage ΔV2 are offset voltages of the first voltage comparison operational amplifier and the second voltage comparison operational amplifier, respectively, wherein the offset voltage is a preset fixed value, and the voltage comparison is performed. The output stage of the two output MOS transistors of the op amp's transconductance operational amplifier is asymmetrically generated to generate the offset voltage. Among them, the ripple current Itran is a mirror current capable of driving other devices.
所述波动电流Itran与预先设定的基准电流Iref叠加生成反馈电流Iramp，根据反馈电流Iramp的幅值生成反馈齿状电压Vramp。可选地，可根据反馈齿状电压Vramp与反馈电压Vcomp(即电压模降压转换器预先设定的基值)的差值生成用于调制的矩形波，从而调节输出占空比。其中，反馈电压Vcomp通过对基准电压Vref与经过降压的输出电压Vout的差值进行放大得到，反馈齿状电压Vramp大于反馈电压Vcomp的部分为矩形波的高电平部分；所述反馈电压Vcomp为经过补偿的电压，补偿电压可使得 反馈电压Vcomp的波形更平缓。The ripple current Itran is superimposed with a preset reference current Iref to generate a feedback current Iramp, and a feedback tooth voltage Vramp is generated according to the magnitude of the feedback current Iramp. Alternatively, a rectangular wave for modulation may be generated according to a difference between the feedback tooth voltage Vramp and the feedback voltage Vcomp (ie, a base value preset by the voltage mode buck converter), thereby adjusting the output duty ratio. The feedback voltage Vcomp is obtained by amplifying the difference between the reference voltage Vref and the stepped output voltage Vout, and the portion of the feedback tooth voltage Vramp greater than the feedback voltage Vcomp is a high level portion of the rectangular wave; the feedback voltage Vcomp For a compensated voltage, the compensation voltage can be made The waveform of the feedback voltage Vcomp is more gradual.
本发明实施例应用的电压模降压转换器的负载瞬态响应增强系统，如图2所示，所述系统包括：低通滤波器、电压比较运放、斜坡发生器ramp、电压生成装置；其中，As shown in FIG. 2, the system includes: a low pass filter, a voltage comparison operational amplifier, a ramp generator ramp, and a voltage generating device; among them,
所述低通滤波器，包括C11和R11，用于对电压模降压转换器的输出电压Vout进行低通滤波，产生平均电压Vout1；The low pass filter, comprising C11 and R11, for low pass filtering the output voltage Vout of the voltage mode buck converter to generate an average voltage Vout1;
所述电压比较运放，配置为计算Vout与Vout1的差值，并将计算得到的差值的幅值波形进行转换得到波动电流Itran；The voltage comparison op amp is configured to calculate a difference between Vout and Vout1, and convert the calculated amplitude waveform of the difference to obtain a ripple current Itran;
所述斜坡发生器，配置为对波动电流Itran的幅值进行斜坡处理；The ramp generator is configured to ramp the amplitude of the ripple current Itran;
所述电压生成装置，配置为根据得到的斜坡信号生成电压模降压转换器的瞬态响应输出电压Vout。The voltage generating device is configured to generate a transient response output voltage Vout of the voltage mode buck converter based on the obtained ramp signal.
例如，所述斜坡发生器对波动电流Itran的幅值进行斜坡处理，生成反馈齿状电压Vramp；For example, the ramp generator ramps the amplitude of the ripple current Itran to generate a feedback dentate voltage Vramp;
相应的，所述电压生成装置，配置为根据反馈齿状电压Vramp与反馈电压Vcomp的差值生成脉宽信号，对所述脉宽信号进行调制生成电压模降压转换器的瞬态响应输出电压Vout；Correspondingly, the voltage generating device is configured to generate a pulse width signal according to a difference between the feedback tooth voltage Vramp and the feedback voltage Vcomp, and modulate the pulse width signal to generate a transient response output voltage of the voltage mode buck converter. Vout;
其中，所述电压生成装置可进一步包括脉宽发生装置PWM和逻辑驱动电路(Logic+Driver)，由脉宽发生装置对反馈齿状电压Vramp进行矩形波化处理，根据反馈齿状电压Vramp与反馈电压Vcomp的差值得到相应脉宽；由逻辑驱动电路对得到的脉宽进行调制，生成电压模降压转换器的瞬态响应输出电压Vout。The voltage generating device may further include a pulse width generating device PWM and a logic driving circuit (Logic+Driver), and the pulse width generating device performs a rectangular wave processing on the feedback tooth voltage Vramp according to the feedback tooth voltage Vramp and the feedback. The difference of the voltage Vcomp is obtained by the corresponding pulse width; the pulse width obtained by the logic driving circuit is modulated to generate a transient response output voltage Vout of the voltage mode buck converter.
所述电压比较运放包括第一电压比较运放gm1和第二电压比较运放gm2，具体结构参照图3和图4；且第一电压比较运放gm1预先设定第一输入阈值电压ΔV1，第二电压比较运放gm2预先设定第二输入阈值电压ΔV2；The voltage comparison operational amplifier includes a first voltage comparison operational amplifier gm1 and a second voltage comparison operational amplifier gm2, the specific structure is referred to FIG. 3 and FIG. 4; and the first voltage comparison operational amplifier gm1 presets the first input threshold voltage ΔV1, The second voltage comparison op amp gm2 presets the second input threshold voltage ΔV2;
相应的，所述电压比较运放将计算得到的差值的幅值波形进行转换得 到波动电流Itran，具体包括：Correspondingly, the voltage comparison op amp converts the amplitude waveform of the calculated difference To the wave current Itran, specifically includes:
当Vout-Vout1-ΔV1大于0时，第一电压比较运放工作，第一电压比较运放根据Vout-Vout1-ΔV1的幅值输出正向波动电流Itran，即：电流流出第一电压比较运放的方向为正向；When Vout-Vout1-ΔV1 is greater than 0, the first voltage is compared with the operational amplifier, and the first voltage comparison op amp outputs the forward ripple current Itran according to the amplitude of Vout-Vout1-ΔV1, that is, the current flows out of the first voltage comparison op amp The direction is positive;
当Vout1-Vout-ΔV2大于0时，第二电压比较运放工作，第二电压比较运放根据Vout1-Vout-ΔV2的幅值输出反向波动电流Itran，即：电流流入第二电压比较运放的方向为反向。When Vout1-Vout-ΔV2 is greater than 0, the second voltage is compared with the operational amplifier, and the second voltage comparison op amp outputs the reverse ripple current Itran according to the amplitude of Vout1-Vout-ΔV2, that is, the current flows into the second voltage comparison op amp The direction is reverse.
所述第一电压比较运放gm1和第二电压比较运放gm2均包括跨导运算放大器和镜像电流电路，所述跨导运算放大器的两个输出MOS管的输出级不对称产生失调电压；其中，所述第一输入阈值电压ΔV1和第二输入阈值电压ΔV2依次为第一电压比较运放和第二电压比较运放的失调电压；所述镜像电流电路位于电压比较运放的输出端，且镜像电流电路中的电流为单方向。其中，波动电流Itran为能够驱动其它设备的镜像电流。The first voltage comparison op amp gm1 and the second voltage comparison op amp gm2 each include a transconductance operational amplifier and a mirror current circuit, and an output stage of the two output MOS transistors of the transconductance operational amplifier generates an offset voltage asymmetrically; The first input threshold voltage ΔV1 and the second input threshold voltage ΔV2 are sequentially the offset voltages of the first voltage comparison operational amplifier and the second voltage comparison operational amplifier; the mirror current circuit is located at the output end of the voltage comparison operational amplifier, and The current in the mirror current circuit is unidirectional. Among them, the ripple current Itran is a mirror current capable of driving other devices.
例如，第一电压比较运放gm1的结构参照图3所示，在设计时，输出级M16＝n-1，M18＝n，这样，输出级的个数不同使得输出端产生固定的失调电压，即第一输入阈值电压ΔV1。当Vout瞬态变化值(Vout-Vout1)小于ΔV1，gm1处于大信号工作状态，由于靠近VIN端的MOS管输出级M18比M16高，因此电压输出点Vgm1的值为VIN，此时输出波动电流Itran＝0；当Vout瞬态变化值(Vout-Vout1)大于ΔV1，即Vout瞬间变高时，Vout-Vout1的值越大，电压输出点Vgm1的电压降低，VIN和Vgm1的压差使得M19和M10导通，从而第一电压比较运放gm1处于放大状态。M19和M10组成镜像电流电路，输出电压Vgm1的幅值控制M19的电流大小，输入的压差(Vout-Vout1)越大，输出电压Vgm1的幅值越低，输出的电流(Itran)越大。其中，对于产生失调电压的部分也可以采用输入级的M11和M12两部分的MOS管个数不匹配，从而产生失调电压ΔV1。其中，第 一电压比较运放gm1只有Vout-Vout1大于ΔV1时才能工作，若小于ΔV1则镜像电流电路的MOS管处于反向截止的状态。For example, the structure of the first voltage comparison op amp gm1 is as shown in FIG. 3. At the time of design, the output stages M16=n-1, M18=n, so that the number of output stages is different, so that the output generates a fixed offset voltage. That is, the first input threshold voltage ΔV1. When the Vout transient change value (Vout-Vout1) is less than ΔV1, gm1 is in a large signal operation state. Since the MOS tube output stage M18 near the VIN terminal is higher than M16, the voltage output point Vgm1 is VIN, and the output ripple current Itran is outputted. =0; When the Vout transient change value (Vout-Vout1) is greater than ΔV1, that is, when Vout instantaneously becomes high, the value of Vout-Vout1 is larger, the voltage of the voltage output point Vgm1 is lowered, and the voltage difference between VIN and Vgm1 is such that M19 and M10 Turned on, so that the first voltage comparison op amp gm1 is in an amplified state. M19 and M10 form a mirror current circuit. The amplitude of the output voltage Vgm1 controls the current of M19. The larger the input voltage difference (Vout-Vout1), the lower the amplitude of the output voltage Vgm1 and the larger the output current (Itran). Wherein, for the portion where the offset voltage is generated, the number of MOS transistors of the M11 and M12 portions of the input stage may be mismatched, thereby generating the offset voltage ΔV1. Among them, the first A voltage comparison op amp gm1 can only work if Vout-Vout1 is greater than ΔV1. If it is less than ΔV1, the MOS transistor of the mirror current circuit is in a reverse-off state.
第二电压比较运放gm2的结构参照图4所示，类似地，结构与第一电压比较运放的结构相近，主要区别在于镜像电流电路的电压参考点不同，例如：在设计时输出级M26＝n，M28＝n-1，产生固定的失调电压，即第二输入阈值电压ΔV2。当Vout瞬态变化差值(Vout1-Vout)小于ΔV2，gm2处于大信号工作状态，由于靠近地线端的MOS管输出级M26比M28高，因此电压输出点Vgm2的值为GND，此时输出波动电流Itran＝0；当Vout瞬态变化值(Vout1-Vout)大于ΔV2时，即Vout瞬间变低时，Vout1-Vout的值越大，电压输出点Vgm2的电压升高，Vgm2和地线的压差使得M29和M20导通，从而第二电压比较运放gm2处于放大状态。M19和M10组成镜像电流电路，输出电压Vgm2的幅值控制M19的电流大小，输入的压差(Vout1-Vout)越大，输出电压Vgm2的幅值越高，输出的电流(Itran)越大。其中，对于产生失调电压的部分也可以采用输入级的M21和M22两部分的MOS管个数不匹配，从而产生失调电压ΔV2。其中第二电压比较运放gm2只有Vout1-Vout大于ΔV2时才能工作，若小于ΔV2则镜像电流电路的MOS管处于反向截止的状态。Referring to FIG. 4, the structure of the second voltage comparison op amp gm2 is similar. The structure is similar to the structure of the first voltage comparison op amp. The main difference is that the voltage reference point of the mirror current circuit is different, for example, the output stage M26 is designed. = n, M28 = n-1, produces a fixed offset voltage, the second input threshold voltage ΔV2. When the Vout transient change difference (Vout1-Vout) is less than ΔV2, gm2 is in a large signal operation state. Since the MOS tube output stage M26 close to the ground terminal is higher than M28, the voltage output point Vgm2 is GND, and the output fluctuation occurs. The current Itran=0; when the Vout transient change value (Vout1-Vout) is greater than ΔV2, that is, when Vout instantaneously becomes lower, the value of Vout1-Vout is larger, the voltage of the voltage output point Vgm2 is increased, and the voltage of Vgm2 and the ground is higher. The difference causes M29 and M20 to be turned on, so that the second voltage is compared with the op amp gm2 in an amplified state. M19 and M10 form a mirror current circuit. The amplitude of the output voltage Vgm2 controls the current of M19. The larger the input voltage difference (Vout1-Vout), the higher the amplitude of the output voltage Vgm2, and the larger the output current (Itran). Wherein, for the portion where the offset voltage is generated, the number of MOS transistors of the two parts of the input stage M21 and M22 may be mismatched, thereby generating the offset voltage ΔV2. The second voltage comparison op amp gm2 can only work if Vout1-Vout is greater than ΔV2. If less than ΔV2, the MOS transistor of the mirror current circuit is in the reverse-off state.
如图5所示，本发明实施例的斜坡发生器ramp的结构示意图，斜坡发生器ramp通过对C1和C2分别充放电产生斜坡信号。本发明实施例的Clk1时钟的占空比为50％，其由clk时钟2分频得到。当clk1上升沿到来时，s1打开，s2闭合，Buf驱动C1，使C1的电压等于Vref。当clk1下降沿到来时，s1闭合，s2打开，Buf 1驱动C2，使C2的电压等于Vref；此时C1已经开始被反馈电流Iramp充电并产生反馈齿状电压Vramp。当下一个clk1上升沿到来时，s1打开，s2闭合，Buf驱动C1，使C1的电压等于Vref；此时C2已经开始被反馈电流Iramp充电并产生反馈齿状电压Vramp。 As shown in FIG. 5, a schematic diagram of the structure of the ramp generator ramp of the embodiment of the present invention, the ramp generator ramp generates a ramp signal by charging and discharging C1 and C2, respectively. The duty ratio of the Clk1 clock of the embodiment of the present invention is 50%, which is obtained by dividing the clk clock by 2. When the rising edge of clk1 comes, s1 turns on, s2 closes, and Buf drives C1, making the voltage of C1 equal to Vref. When the falling edge of clk1 comes, s1 is closed, s2 is turned on, Buf 1 drives C2, so that the voltage of C2 is equal to Vref; at this time, C1 has begun to be charged by the feedback current Iramp and generates a feedback dent voltage Vramp. When the next rising edge of clk1 comes, s1 is turned on, s2 is closed, and Buf drives C1, so that the voltage of C1 is equal to Vref; at this time, C2 has begun to be charged by the feedback current Iramp and generates a feedback dent voltage Vramp.
如此反复，交替切换充放电电容的方式，给Buf一个clk时钟周期的时间对电容进行充电从而稳定电容的初始电压，可以防止单个电容在切换瞬间电压还没有稳定就开始使用生成斜坡电压，避免两个连续的斜坡信号的初始电压不相等，从而造成PWM波的占空比不准确。Repeatedly, alternately switching the charge and discharge capacitors, giving Buf a clk clock cycle to charge the capacitor to stabilize the initial voltage of the capacitor, which can prevent the single capacitor from starting to use the generated ramp voltage when the switching voltage is not stable, avoiding two The initial voltages of successive ramp signals are not equal, resulting in inaccurate duty cycle of the PWM wave.
由于波动电流Itran的幅值较低直接应用不方便，带载能力弱，因此，所述斜坡发生器ramp先将所述波动电流Itran与预先设定的基准电流Iref叠加生成反馈电流Iramp，再根据反馈电流Iramp的幅值生成反馈齿状电压Vramp。Since the amplitude of the wave current Itran is low, the direct application is inconvenient, and the load capacity is weak. Therefore, the ramp generator ramp first superimposes the wave current Itran with a preset reference current Iref to generate a feedback current Iramp, and then according to The magnitude of the feedback current Iramp generates a feedback tooth voltage Vramp.
同理，所述系统还包括误差放大器(EA)，基准电压Vref与经过降压的输出电压Vout通过误差放大器生成反馈电压Vcomp；相应的，脉宽发生装置根据反馈齿状电压Vramp与反馈电压Vcomp的差值生成用于调制的矩形波，反馈齿状电压Vramp大于反馈电压Vcomp的部分为PWM的高电平部分。Similarly, the system further includes an error amplifier (EA), and the reference voltage Vref and the stepped output voltage Vout generate a feedback voltage Vcomp through the error amplifier; correspondingly, the pulse width generating device according to the feedback tooth voltage Vramp and the feedback voltage Vcomp The difference value generates a rectangular wave for modulation, and the portion where the feedback tooth voltage Vramp is larger than the feedback voltage Vcomp is a high level portion of the PWM.
所述系统还包括补偿网络compensation，所述反馈电压Vcomp为经过补偿网络compensation补偿的电压，从而使得反馈电压Vcomp形成平缓的波形。The system also includes a compensation network compensation, the feedback voltage Vcomp being a voltage compensated by the compensation network compensation such that the feedback voltage Vcomp forms a gradual waveform.
如图6所示，其中Iload为负载电流，IL为电感电流(图2中电感L的电流)。当负载电流Iload突然减小时，滤波网络(图2中的Co和L组成的电源滤波网络)无法维持Vout稳定，Vout电压迅速上升；当Vout和Vout1电压差大于第一电压比较运放gm1的第一输入阈值电压ΔV1后，电压输出点Vgm1的电压下降，从而控制产生与电压差值相应的波动电流Itran，这里电流的产生过程与前文原理类似，此处不再累述。As shown in Figure 6, where Iload is the load current and IL is the inductor current (the current of inductor L in Figure 2). When the load current Iload suddenly decreases, the filter network (the power filter network composed of Co and L in Figure 2) cannot maintain Vout stable, and the Vout voltage rises rapidly; when the voltage difference between Vout and Vout1 is greater than the first voltage, the first of the op amps gm1 After an input threshold voltage ΔV1, the voltage of the voltage output point Vgm1 drops, thereby controlling the generation of the ripple current Itran corresponding to the voltage difference, where the current generation process is similar to the previous principle and will not be described here.
基准电流Iref和波动电流Itran叠加后产生反馈电流Iramp，反馈电流Iramp电流增大，例如，若以流出第一电压比较运放的方向为正向，正向为电流增大的方向，相当于电流被灌入基准电流Iref，使得基准电流增大；同 时，产生的反馈齿状电压Vramp斜坡信号斜率变大；反馈齿状电压Vramp与反馈电压Vcomp进行比较，从而形成PWM波，由于反馈齿状电压Vramp的斜率较大，输出的PWM波脉宽变大，从而控制hd和ld引起引起占空比SW变小，电感电流IL迅速下降，同时Vout下降，从而达到快速调整输出电压Vout的目的。The reference current Iref and the ripple current Itran are superimposed to generate a feedback current Iramp, and the feedback current Iramp current is increased. For example, if the direction of the op amp is forward in the forward direction by the first voltage, the forward direction is the direction in which the current increases, which is equivalent to the current. Is filled into the reference current Iref, so that the reference current is increased; When the feedback tooth voltage Vramp ramp signal slope becomes larger, the feedback tooth voltage Vramp is compared with the feedback voltage Vcomp to form a PWM wave. Since the slope of the feedback tooth voltage Vramp is large, the PWM pulse width of the output changes. Large, thus controlling hd and ld causes the duty cycle SW to become smaller, the inductor current IL drops rapidly, and Vout drops, thereby achieving the purpose of rapidly adjusting the output voltage Vout.
如图7所示，其中Iload为负载电流，IL为电感电流(图2中电感L的电流)。当负载电流Iload突然增大时，滤波网络(图2中的Co和L组成的电源滤波网络)无法维持Vout稳定，Vout电压迅速下降；当Vout1和Vout电压差大于第二电压比较运放gm2的第二输入阈值电压ΔV2后，电压输出点Vgm2的电压上升，从而控制产生与电压差值相应的波动电流Itran，这里电流的产生过程与前文原理类似，此处不再累述。As shown in Figure 7, where Iload is the load current and IL is the inductor current (the current of inductor L in Figure 2). When the load current Iload suddenly increases, the filter network (the power filter network composed of Co and L in Figure 2) cannot maintain Vout stable, and the Vout voltage drops rapidly; when the Vout1 and Vout voltage difference is greater than the second voltage, the op amp gm2 After the second input threshold voltage ΔV2, the voltage of the voltage output point Vgm2 rises, thereby controlling the generation of the ripple current Itran corresponding to the voltage difference, where the current generation process is similar to the previous principle and will not be described here.
基准电流Iref和波动电流Itran叠加后产生反馈电流Iramp，反馈电流Iramp电流减小，例如，若以流入第一电压比较运放的方向为负向，负向为电流减小的方向，相当于电流被抽出基准电流Iref，使得基准电流减小；同时，产生的反馈齿状电压Vramp斜坡信号斜率减小；反馈齿状电压Vramp与反馈电压Vcomp进行比较，从而形成PWM波，由于反馈齿状电压Vramp的斜率较小，输出的PWM波脉宽变小，从而控制hd和ld引起引起占空比SW变小，电感电流IL迅速上升，同时Vout上升，从而达到快速调整输出电压Vout的目的。The reference current Iref and the ripple current Itran are superimposed to generate a feedback current Iramp, and the feedback current Iramp current is decreased. For example, if the direction of the op amp is negative in the negative direction, the negative direction is the direction in which the current decreases, which is equivalent to the current. The reference current Iref is extracted to reduce the reference current; at the same time, the generated feedback tooth voltage Vramp ramp signal slope is decreased; the feedback tooth voltage Vramp is compared with the feedback voltage Vcomp to form a PWM wave due to the feedback tooth voltage Vramp The slope of the PWM wave is small, and the PWM pulse width of the output becomes smaller, so that the control of hd and ld causes the duty ratio SW to become smaller, the inductor current IL rises rapidly, and Vout rises, thereby achieving the purpose of rapidly adjusting the output voltage Vout.
以上所述，仅为本发明的较佳实施例而已，并非用于限定本发明的保护范围，凡按照本发明原理所作的修改，都应当理解为落入本发明的保护范围。The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and modifications made in accordance with the principles of the present invention are understood to fall within the scope of the present invention.
工业实用性Industrial applicability
本发明实施例中，供的电压模降压转换器的负载瞬态响应增强方法及系统，通过对电压模降压转换器的输出电压Vout进行低通滤波，产生平均 电压Vout1，对Vout和Vout1进行差值计算，并将计算得到的差值的幅值波形转换为波动电流；再通过对波动电流的幅值进行斜坡处理，根据得到的斜坡信号生成电压模降压转换器的瞬态响应输出电压Vout，可提升电压模降压转换器的负载瞬态响应能力，且方便工业生产和制作。 In the embodiment of the present invention, the load transient response enhancement method and system for the voltage mode buck converter are low-pass filtered by the output voltage Vout of the voltage mode buck converter to generate an average The voltage Vout1 calculates the difference between Vout and Vout1, and converts the amplitude waveform of the calculated difference into a fluctuating current; and then slopes the amplitude of the fluctuating current to generate a voltage mode buck according to the obtained ramp signal. The converter's transient response output voltage, Vout, improves the load transient response of the voltage-mode buck converter and is convenient for industrial production and fabrication.

Claims (12)

  1. 一种电压模降压转换器的负载瞬态响应增强方法，所述方法包括：A load transient response enhancement method for a voltage mode buck converter, the method comprising:
    对电压模降压转换器的输出电压Vout进行低通滤波，产生平均电压Vout1；Low-pass filtering the output voltage Vout of the voltage mode buck converter to generate an average voltage Vout1;
    计算Vout与Vout1的差值，并将计算得到的差值的幅值波形进行转换得到波动电流Itran；Calculating the difference between Vout and Vout1, and converting the amplitude waveform of the calculated difference to obtain a ripple current Itran;
    对波动电流Itran的幅值进行斜坡处理，根据得到的斜坡信号生成电压模降压转换器的瞬态响应输出电压Vout。The amplitude of the fluctuating current Itran is ramped, and the transient response output voltage Vout of the voltage mode buck converter is generated according to the obtained ramp signal.
  2. 根据权利要求1所述的方法，其中，所述对波动电流Itran的幅值进行斜坡处理，根据得到的斜坡信号生成电压模降压转换器的瞬态响应输出电压Vout，包括：The method of claim 1 wherein said ramping the amplitude of the ripple current Itran and generating a transient response output voltage Vout of the voltage mode buck converter based on the resulting ramp signal comprises:
    先对波动电流Itran的幅值进行斜坡处理，生成反馈齿状电压Vramp；再根据反馈齿状电压Vramp单位周期内的脉宽，调制生成电压模降压转换器的瞬态响应输出电压Vout。First, the amplitude of the ripple current Itran is ramped to generate a feedback tooth voltage Vramp; and the transient response output voltage Vout of the voltage mode buck converter is modulated according to the pulse width of the feedback tooth voltage Vramp unit period.
  3. 根据权利要求1所述的方法，其中，所述方法还包括：预先设定第一输入阈值电压ΔV1和第二输入阈值电压ΔV2；The method of claim 1, wherein the method further comprises: presetting a first input threshold voltage ΔV1 and a second input threshold voltage ΔV2;
    所述将计算得到的差值的幅值波形进行转换得到波动电流Itran，包括：The converting the amplitude waveform of the calculated difference to obtain the ripple current Itran includes:
    当Vout-Vout1大于ΔV1时，将Vout-Vout1-ΔV1的幅值波形转换为相应波形的波动电流Itran，所述得到的波动电流Itran为正向电流；When Vout-Vout1 is greater than ΔV1, the amplitude waveform of Vout-Vout1-ΔV1 is converted into the ripple current Itran of the corresponding waveform, and the obtained ripple current Itran is a forward current;
    当Vout-Vout1的差值大于零且小于ΔV1时，不产生波动电流Itran；When the difference of Vout-Vout1 is greater than zero and less than ΔV1, no fluctuating current Itran is generated;
    当Vout1-Vout大于ΔV2时，将Vout1-Vout-ΔV2的幅值波形转换为相应波形的波动电流Itran，所述得到的波动电流Itran为反向电流；When Vout1-Vout is greater than ΔV2, the amplitude waveform of Vout1-Vout-ΔV2 is converted into the ripple current Itran of the corresponding waveform, and the obtained ripple current Itran is a reverse current;
    当Vout1-Vout的差值大于零且小于ΔV2时，不产生波动电流Itran。When the difference between Vout1 - Vout is greater than zero and less than ΔV2, the ripple current Itran is not generated.
  4. 根据权利要求2所述的方法，其中，所述生成反馈齿状电压Vramp 包括：The method of claim 2, wherein said generating a dentate voltage Vramp include:
    将所述波动电流Itran与预先设定的基准电流Iref叠加生成反馈电流Iramp，根据反馈电流Iramp的幅值生成反馈齿状电压Vramp。The ripple current Itran is superimposed with a preset reference current Iref to generate a feedback current Iramp, and a feedback tooth voltage Vramp is generated according to the magnitude of the feedback current Iramp.
  5. 根据权利要求4所述的方法，其中，所述方法还包括：根据反馈齿状电压Vramp与反馈电压Vcomp的差值生成用于调制的矩形波；其中，反馈电压Vcomp通过对基准电压Vref与经过分压的输出电压Vout的差值进行放大得到，反馈齿状电压Vramp大于反馈电压Vcomp的部分为矩形波的高电平部分。The method according to claim 4, wherein the method further comprises: generating a rectangular wave for modulation based on a difference between the feedback tooth voltage Vramp and the feedback voltage Vcomp; wherein the feedback voltage Vcomp passes through the reference voltage Vref and The difference between the divided output voltages Vout is amplified, and the portion of the feedback tooth voltage Vramp that is larger than the feedback voltage Vcomp is a high-level portion of the rectangular wave.
  6. 根据权利要求3所述的方法，其中，所述第一输入阈值电压ΔV1和第二输入阈值电压ΔV2依次为第一电压比较运放和第二电压比较运放的失调电压；其中，所述失调电压为预先设定的固定值，所述失调电压由电压比较运放的跨导运算放大器的两个输出MOS管的输出级不对称产生。The method of claim 3, wherein the first input threshold voltage ΔV1 and the second input threshold voltage ΔV2 are, in turn, an offset voltage of the first voltage comparison op amp and the second voltage comparison op amp; wherein the offset The voltage is a predetermined fixed value that is generated asymmetrically by the output stages of the two output MOS transistors of the voltage transconductance operational amplifier.
  7. 一种电压模降压转换器的负载瞬态响应增强系统，所述系统包括低通滤波器、电压比较运放、斜坡发生器和电压生成装置；其中，A load transient response enhancement system for a voltage mode buck converter, the system comprising a low pass filter, a voltage comparison op amp, a ramp generator, and a voltage generating device;
    所述低通滤波器，配置为对电压模降压转换器的输出电压Vout进行低通滤波，产生平均电压Vout1；The low pass filter is configured to low pass filter the output voltage Vout of the voltage mode buck converter to generate an average voltage Vout1;
    所述电压比较运放，配置为计算Vout与Vout1的差值，并将计算得到的差值的幅值波形进行转换得到波动电流Itran；The voltage comparison op amp is configured to calculate a difference between Vout and Vout1, and convert the calculated amplitude waveform of the difference to obtain a ripple current Itran;
    所述斜坡发生器，配置为对波动电流Itran的幅值进行斜坡处理；The ramp generator is configured to ramp the amplitude of the ripple current Itran;
    所述电压生成装置，配置为根据得到的斜坡信号生成电压模降压转换器的瞬态响应输出电压Vout。The voltage generating device is configured to generate a transient response output voltage Vout of the voltage mode buck converter based on the obtained ramp signal.
  8. 根据权利要求7所述的系统，其中，所述电压比较运放包括：第一电压比较运放和第二电压比较运放；The system of claim 7 wherein said voltage comparison op amp comprises: a first voltage comparison op amp and a second voltage comparison op amp;
    其中，第一电压比较运放预先设定第一输入阈值电压ΔV1，第二电压比较运放预先设定第二输入阈值电压ΔV2； The first voltage comparison op amp presets a first input threshold voltage ΔV1, and the second voltage comparison op amp presets a second input threshold voltage ΔV2;
    当Vout-Vout1-ΔV1大于零时，第一电压比较运放工作，第一电压比较运放根据Vout-Vout1-ΔV1的幅值输出正向波动电流Itran；When Vout-Vout1-ΔV1 is greater than zero, the first voltage is compared with the operational amplifier, and the first voltage comparison op amp outputs the forward ripple current Itran according to the amplitude of Vout-Vout1-ΔV1;
    当Vout1-Vout-ΔV2大于零时，第二电压比较运放工作，第二电压比较运放根据Vout1-Vout-ΔV2的幅值输出反向波动电流Itran。When Vout1-Vout-ΔV2 is greater than zero, the second voltage is compared with the operational amplifier, and the second voltage comparison op amp outputs the reverse ripple current Itran according to the magnitude of Vout1-Vout-ΔV2.
  9. 根据权利要求7或8所述的系统，其中，所述斜坡发生器，配置为将所述波动电流Itran与预先设定的基准电流Iref叠加生成反馈电流Iramp，根据反馈电流Iramp的幅值生成反馈齿状电压Vramp。The system according to claim 7 or 8, wherein said ramp generator is configured to superimpose said ripple current Itran with a preset reference current Iref to generate a feedback current Iramp, and generate feedback based on the magnitude of the feedback current Iramp Toothed voltage Vramp.
  10. 根据权利要求9所述的系统，其中，所述系统还包括误差放大器EA，配置为于根据基准电压Vref与经过分压的输出电压Vout生成反馈电压Vcomp；The system of claim 9, wherein the system further comprises an error amplifier EA configured to generate a feedback voltage Vcomp according to the reference voltage Vref and the divided output voltage Vout;
    相应的，所述电压生成装置，配置为根据反馈齿状电压Vramp与反馈电压Vcomp的差值生成脉宽信号，对所述脉宽信号进行调制生成电压模降压转换器的瞬态响应输出电压Vout。Correspondingly, the voltage generating device is configured to generate a pulse width signal according to a difference between the feedback tooth voltage Vramp and the feedback voltage Vcomp, and modulate the pulse width signal to generate a transient response output voltage of the voltage mode buck converter. Vout.
  11. 根据权利要求10所述的系统，其中，所述系统还包括补偿网络compensation，所述反馈电压Vcomp为经过补偿网络compensation补偿的电压。The system of claim 10 wherein said system further comprises compensation network compensation, said feedback voltage Vcomp being a voltage compensated by compensation network compensation.
  12. 根据权利要求8所述的系统，其中，所述第一电压比较运放和第二电压比较运放均包括跨导运算放大器和镜像电流电路；The system of claim 8 wherein said first voltage comparison op amp and said second voltage comparison op amp each comprise a transconductance operational amplifier and a mirror current circuit;
    所述跨导运算放大器的两个输出MOS管的输出级不对称产生失调电压；所述第一输入阈值电压ΔV1和第二输入阈值电压ΔV2依次为第一电压比较运放和第二电压比较运放的失调电压；An output stage of the two output MOS transistors of the transconductance operational amplifier is asymmetrically generated with an offset voltage; the first input threshold voltage ΔV1 and the second input threshold voltage ΔV2 are sequentially a first voltage comparison operational amplifier and a second voltage comparison operation Offset voltage
    所述镜像电流电路位于电压比较运放的输出端，且所述镜像电流电路的电流为单方向。 The mirror current circuit is located at an output of the voltage comparison op amp, and the current of the mirror current circuit is unidirectional.
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