WO2017143884A1 - Method of controlling comparator and control circuit - Google Patents

Method of controlling comparator and control circuit Download PDF

Info

Publication number
WO2017143884A1
WO2017143884A1 PCT/CN2017/071107 CN2017071107W WO2017143884A1 WO 2017143884 A1 WO2017143884 A1 WO 2017143884A1 CN 2017071107 W CN2017071107 W CN 2017071107W WO 2017143884 A1 WO2017143884 A1 WO 2017143884A1
Authority
WO
WIPO (PCT)
Prior art keywords
inductor current
zero
converter
comparator
synchronous rectification
Prior art date
Application number
PCT/CN2017/071107
Other languages
French (fr)
Chinese (zh)
Inventor
张亮
彭祥
Original Assignee
熠芯(珠海)微电子研究院有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 熠芯(珠海)微电子研究院有限公司 filed Critical 熠芯(珠海)微电子研究院有限公司
Publication of WO2017143884A1 publication Critical patent/WO2017143884A1/en

Links

Images

Classifications

    • 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
    • H02M3/158—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 including plural semiconductor devices as final control devices for a single load
    • 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
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/21—Conversion of ac power input into dc power output without possibility of reversal 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
    • H02M7/217—Conversion of ac power input into dc power output without possibility of reversal 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
    • 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
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/21—Conversion of ac power input into dc power output without possibility of reversal 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
    • H02M7/217—Conversion of ac power input into dc power output without possibility of reversal 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
    • H02M7/219—Conversion of ac power input into dc power output without possibility of reversal 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 in a bridge configuration
    • H02M7/2195—Conversion of ac power input into dc power output without possibility of reversal 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 in a bridge configuration the switches being synchronously commutated at the same frequency of the AC input voltage
    • 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
    • H02M1/0009—Devices or circuits for detecting current in a converter
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Definitions

  • the present application relates to the field of power electronics, and in particular, to a control method and a control circuit for a comparator in an inductor current zero-crossing detection circuit of a synchronous rectifier converter.
  • synchronous rectification converters have been widely used in various fields. Since the freewheeling switching tubes in synchronous rectification converters do not have single-conductivity, the main switching tubes in the synchronous rectification converters are turned off and freewheeling switches. When the tube is turned on, if the load current is small, the inductor current in the synchronous rectification converter will be reversed, so that the synchronous rectification converter operates in a forced CCM (Continuous Conduction Mode), which affects the synchronous rectification converter. effectiveness.
  • CCM Continuous Conduction Mode
  • an inductor current zero-crossing detection circuit is often provided in the synchronous rectification converter.
  • the detection circuit is mainly implemented by a comparator CMP_ZERO; specifically, when synchronous rectification is performed
  • the comparator CMP_ZERO compares the magnitude of the drain voltage and the source voltage of the freewheeling switch tube Q2, and the current in the inductor L is reversed.
  • the drain voltage of the freewheeling switch Q2 is greater than the source voltage
  • the comparator CMP_ZERO is inverted, and a high level signal is output to the driving circuit.
  • the driving circuit After receiving the high level signal outputted by the comparator CMP_ZERO, the driving circuit generates a logic signal to turn off the freewheeling switch tube Q2, so that the synchronous rectification converter operates in the DCM (Discontinuous Conduction mode), which can reduce the continuation.
  • the power loss of the flow switch tube Q2 increases the efficiency of the synchronous rectifier converter.
  • the zero-crossing detection of the inductor current of the synchronous rectifier converter is not accurate, so that the synchronous rectification transformation The efficiency of the device is still very low.
  • the present invention provides a control method and a control circuit for a comparator in an inductor current zero-crossing detection circuit of a synchronous rectifier converter, which is used to solve the problem that the accuracy of the zero-crossing detection of the synchronous current of the synchronous rectifier converter is low.
  • the application provides a method for controlling a comparator, including:
  • the synchronous rectification conversion According to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than or equal to zero, the synchronous rectification conversion is controlled.
  • the inductor current zero-crossing detects the offset voltage of the comparator in the circuit.
  • Controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter specifically including:
  • Controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter specifically including:
  • the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current has passed zero and the body diode of the freewheeling switching tube of the synchronous rectifier converter is turned on, the inductor current of the synchronous rectifier converter is controlled. The offset voltage of the comparator in the zero detection circuit is reduced.
  • Controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter specifically including:
  • the inductor current zero-crossing detection circuit of the synchronous rectifier converter When the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current does not zero, and the inductor current of the synchronous rectifier converter is not less than or equal to zero, the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled. The offset voltage of the comparator does not change.
  • the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled, and specifically includes:
  • the application also provides a control circuit for the comparator, comprising:
  • a body diode detecting unit configured to detect whether a body diode of the freewheeling switch tube of the synchronous rectifier converter is turned on;
  • An inductance detecting unit configured to detect whether an inductor current of the synchronous rectifier converter is less than or equal to zero
  • control unit configured to: according to an output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is Less than or equal to zero, the offset current of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled.
  • control unit is specifically configured to: when the body diode of the freewheeling switch of the synchronous rectifier converter is not turned on, and the inductor current of the synchronous rectifier converter is less than or equal to zero, the inductor current of the synchronous rectifier converter is controlled.
  • the offset voltage of the comparator in the zero detection circuit increases.
  • control unit is specifically configured to: when the output current of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current has crossed zero, the body diode of the freewheeling switch tube of the synchronous rectifier converter When turned on, the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled to decrease.
  • control unit is specifically configured to: when an output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current does not cross zero, and the inductor current of the synchronous rectifier converter is not less than or equal to zero, The offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled.
  • control unit is specifically configured to: when the offset voltage of the comparator is changed in the inductor current zero-crossing detection circuit of the synchronous rectifier converter, control the change amplitude according to the historical data.
  • the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and the inductance of the synchronous rectification converter Whether the current is less than or equal to zero is used to comprehensively judge the working state of the synchronous rectifier converter, thereby dynamically controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter, which can reduce the circuit delay and process deviation.
  • the effect is to improve the detection accuracy of the inductor current zero-crossing detection circuit of the synchronous rectifier converter.
  • FIG. 1 is a schematic structural view of an inductor current zero-crossing detecting circuit of a synchronous rectification converter in the prior art
  • FIG. 2 is a schematic flow chart of a method for controlling a comparator in an inductor current zero-crossing detecting circuit of a synchronous rectification converter according to an embodiment of the present disclosure
  • FIG. 3 is a schematic structural diagram of a control circuit of a comparator in an inductor current zero-crossing detecting circuit of a synchronous rectification converter according to an embodiment of the present application;
  • FIG. 4 is a schematic structural diagram of a control circuit of a comparator in an inductor current zero-crossing detecting circuit of a synchronous rectification converter according to an embodiment of the present application;
  • FIG. 5 is a schematic structural diagram of a voltage adjustment subunit in a control unit of a comparator control circuit of an inductor current zero-crossing detection circuit of a synchronous rectification converter according to an embodiment of the present disclosure
  • FIG. 6 is a second schematic structural diagram of a voltage adjustment subunit in a control unit of a comparator control circuit of a synchronous current rectifier zero-crossing detection circuit according to an embodiment of the present application;
  • FIG. 7 is a schematic diagram of a working sequence diagram of a logic control subunit in a control unit of a comparator control circuit of a synchronous current rectifier zero-crossing detection circuit according to an embodiment of the present invention
  • FIG. 8 is a second schematic diagram of the operation timing of the logic control subunit in the control unit of the comparator control circuit of the synchronous current rectifier zero-crossing detection circuit of the synchronous rectifier converter according to the embodiment of the present invention
  • FIG. 9 is a third schematic diagram of the operation timing of the logic control subunit in the control unit of the comparator control circuit of the synchronous current rectifier zero-crossing detection circuit of the synchronous rectifier converter according to the embodiment of the present invention.
  • FIG. 10 is a fourth working sequence diagram of a logic control subunit in a control unit of a comparator control circuit of a synchronous current rectifier zero-crossing detection circuit according to an embodiment of the present invention
  • FIG. 11 is a fifth schematic diagram of the operation timing of the logic control subunit in the control unit of the comparator control circuit of the synchronous current rectifier zero-crossing detection circuit of the synchronous rectifier converter according to the embodiment of the present application.
  • the embodiment of the present application provides a comparator control method and a control circuit for improving the detection precision of the inductor current zero-crossing detection circuit of the synchronous rectifier converter.
  • the preferred embodiments of the present application are described with reference to the accompanying drawings, and the preferred embodiments described herein are intended to illustrate and explain the invention. And in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.
  • the embodiment of the present application provides a control method for a comparator, which is applied to an inductor current zero-crossing detection circuit of a synchronous rectifier converter.
  • the control method is as shown in FIG. 2, and specifically includes the following steps:
  • Step 101 Detect whether a body diode of a freewheeling switch tube of the synchronous rectifier converter is turned on, and whether an inductor current of the synchronous rectifier converter is less than or equal to zero;
  • Step 102 According to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than or equal to zero, the control is performed.
  • the offset current of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is performed.
  • the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is used to compare the drain voltage and the source voltage of the freewheeling switching tube of the synchronous rectifier converter.
  • step 102 according to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than Equal to zero, controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter, which may specifically include:
  • the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates the inductor power Whether the current crosses zero or not, and controls the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter to increase;
  • the control method of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter provided by the embodiment of the present application, according to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, and the continuation of the synchronous rectification converter
  • the three factors of whether the body diode of the flow switching tube is turned on and whether the inductor current of the synchronous rectifier converter is less than or equal to zero are comprehensively judged to determine the working state of the synchronous rectifier converter, thereby dynamically controlling the inductor current zero-crossing detecting circuit of the synchronous rectifier converter
  • the offset voltage of the comparator can reduce the influence of circuit delay and process deviation, improve the detection accuracy of the inductor current zero-crossing detection circuit of the synchronous rectifier converter, and make the switch-off position of the freewheeling switch tube in the synchronous rectifier converter more ideal.
  • the inductor current zero-crossing detection circuit of the synchronous rectifier converter detects that the inductor current does not cross zero, the body diode of the freewheeling switch of the synchronous rectifier converter is not turned on, and the inductor current of the synchronous rectifier converter When not less than or equal to zero, at this time, the synchronous rectification converter operates in CCM, and the inductor current does not cross zero, and the freewheeling switch tube is not turned off in advance, the offset voltage of the comparator does not need to be adjusted;
  • the inductor current zero-crossing detection circuit of the synchronous rectifier converter detects that the inductor current does not cross zero, the body diode of the free-wheeling switch of the synchronous rectifier converter is turned on, and the inductor current of the synchronous rectifier converter is not When it is less than or equal to zero, at this time, the synchronous rectification converter operates in CCM, and the inductor current does not cross zero, and the freewheeling switch tube is not turned off in advance, the offset voltage of the comparator does not need to be adjusted;
  • the inductor current zero-crossing detection circuit of the synchronous rectifier converter detects that the inductor current does not cross zero, the body diode of the freewheeling switch of the synchronous rectifier converter is not turned on, and the inductor current of the synchronous rectifier converter
  • the synchronous rectification converter operates in CCM, and the inductor current has passed zero, that is, the CCM is forced, and the offset voltage of the comparator needs to be increased;
  • the inductor current zero-crossing detection circuit of the synchronous rectifier converter detects that the inductor current has passed zero, the body diode of the free-wheeling switch of the synchronous rectifier converter is turned on, and the inductor current of the synchronous rectifier converter is not When the value is less than or equal to zero, at this time, the synchronous rectification converter operates in CCM, and the inductor current does not cross zero, and the freewheeling switch tube is turned off in advance, the offset voltage of the comparator needs to be reduced;
  • the inductor current zero-crossing detection circuit of the synchronous rectifier converter detects that the inductor current does not cross zero, the body diode of the free-wheeling switch of the synchronous rectifier converter is turned on, and the inductor current of the synchronous rectifier converter is less than When it is equal to zero, it is the error working state, usually does not appear; at this time, the offset voltage of the comparator does not need to be adjusted;
  • step 102 when the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is changed, the magnitude of the change can be controlled according to the historical data.
  • the embodiment of the present application further provides a control circuit of the comparator, which is applied to the inductor current zero-crossing detection circuit of the synchronous rectifier converter, and the control
  • the circuit as shown in FIG. 3, may specifically include the following units:
  • the body diode detecting unit 301 is configured to detect whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on;
  • the inductor detecting unit 302 is configured to detect whether the inductor current of the synchronous rectifier converter is less than or equal to zero;
  • the control unit 303 is configured to: according to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than Equal to zero, controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter.
  • the control unit 303 is specifically configured to: when the body diode of the freewheeling switch of the synchronous rectifier converter is not turned on, and the inductor current of the synchronous rectifier converter is less than or equal to zero, regardless of the inductor current zero-crossing detection circuit of the synchronous rectifier converter
  • the output signal of the middle comparator indicates whether the inductor current crosses zero, and both control the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter to increase.
  • control unit 303 is further configured to: when the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter indicates that the inductor current has passed zero, the body diode guide of the freewheeling switch tube of the synchronous rectification converter When the inductor current of the synchronous rectifier converter is less than or equal to zero, the inductor current of the synchronous rectifier converter is controlled. The offset voltage of the comparator in the zero-crossing detection circuit is reduced.
  • control unit 303 is further specifically configured to: in other cases, for example, when the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current does not cross zero, the inductor current of the synchronous rectifier converter When not less than or equal to zero, the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled regardless of whether the body diode of the freewheeling switching tube of the synchronous rectifier converter is turned on.
  • control unit 303 can also control the change amplitude according to the historical data when the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is changed.
  • the body diode detecting unit 301 can be implemented by using a comparator CMP_DIO
  • the inductor detecting unit 302 can be implemented by using a comparator CMP_ILN and an anti-ringing circuit
  • the control unit 303 can adopt a logic control sub-unit, plus Subtract counter and voltage adjustment subunit implementation.
  • the output signal ZRDT of the comparator CMP_ZERO in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is output to the drive circuit on the one hand, and participates in the turn-off control of the freewheeling switch tube, and is output to the logic control sub-unit on the other hand to participate in the synchronization.
  • the judgment of the operating state of the rectifier converter is made by the comparator CMP_ZERO in the inductor current zero-crossing detection circuit of the synchronous rectifier converter.
  • the freewheeling switch tube When the freewheeling switch tube is turned off, if the inductor current I L is greater than zero, the body diode of the freewheeling switch tube is turned on, and the drain voltage L X of the freewheeling switch tube is about -700 mV, so the reference voltage VREF1 can be used. The value ranges from 0.3V to 0.6V. Based on this characteristic, it can be detected whether the body diode of the freewheeling switch tube is turned on, and the output signal ZDIO of the comparator CMP_DIO represents the detection result and is output to the logic control subunit.
  • the anti-ringing circuit is turned on. If the inductor current is less than or equal to zero, the drain voltage L X of the freewheeling switch tube will eventually rise to the time when the main switching tube and the freewheeling switching tube are simultaneously turned off. It is greater than or equal to the output voltage Vo, so the value of the reference voltage VREF2 can be in the range of 200 mV to Vo. Based on this characteristic, it can be detected whether the inductor current is less than or equal to zero, and the output signal ZILN of the comparator CMP_ILN characterizes the detection result and is output to the logic control subunit.
  • the logic control subunit is configured to determine the operating state of the synchronous rectifier converter, and output the control signals UP (increase), DN (decrease), and HOLD (hold) of the comparator offset voltage to the up-down counter.
  • the up-down counter is used to accumulate or decrement the count.
  • the number of count bits N determines the number of comparator offset voltage adjustment gears.
  • the output signal ZR_CL[N-1:0] is output to the voltage adjustment sub-unit.
  • the driving circuit receives the output signal of the comparator CMP_ZERO, drives the main switch tube and the freewheeling switch tube, and also outputs the NGATE and PGATE signals to the logic control sub-unit (not shown in FIG. 4) to control the logic timing.
  • a reference voltage VREF3 is also superimposed on the DCGND of the power supply. The magnitude of the reference voltage VREF3 is equal to half of the voltage regulation range of the resistor string in the dotted line.
  • the circuit shown in FIG. 5 above is merely an example and is not intended to limit the application.
  • the voltage adjustment subunit in the control circuit of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter provided by the embodiment of the present application can also be implemented in other manners, for example, as shown in FIG. 6, and will not be described in detail herein.
  • the detection precision of the inductor current zero-crossing detection circuit of the synchronous rectifier converter can be improved, and the working efficiency of the synchronous rectifier converter can be improved.

Abstract

Provided are a method of controlling a comparator and a control circuit, increasing detection precision of a zero-crossing detection circuit that detects an inductor current in a synchronous rectification converter. The control method comprises: detecting whether a body diode in a current control transistor switch of a synchronous rectification converter is conducting, and whether an inductor current in the synchronous rectification converter is less than or equal to zero (101); and controlling, according to an output signal of a comparator in an inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the current control transistor switch of the synchronous rectification converter is conducting, and whether the inductor current in the synchronous rectification converter is less than or equal to zero, an unbalanced voltage of the comparator of the inductor current zero-crossing detection circuit of the synchronous rectification converter (102).

Description

一种比较器的控制方法及控制电路Control method and control circuit of comparator
本申请要求在2016年02月24日提交中国专利局、申请号为201610102859.2、发明名称为“一种比较器的控制方法及控制电路”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。This application claims priority to Chinese Patent Application No. 201610102859.2, entitled "Control Method and Control Circuit of a Comparator", filed on February 24, 2016, the entire contents of which are incorporated by reference. In this application.
技术领域Technical field
本申请涉及电力电子技术领域，尤其涉及一种同步整流变换器的电感电流过零检测电路中比较器的控制方法及控制电路。The present application relates to the field of power electronics, and in particular, to a control method and a control circuit for a comparator in an inductor current zero-crossing detection circuit of a synchronous rectifier converter.
背景技术Background technique
目前，同步整流变换器已在各领域得到了广泛应用，由于同步整流变换器中的续流开关管不具备单向导通性，因此当同步整流变换器中的主开关管关断、续流开关管导通时，如果负载电流较小，同步整流变换器中的电感电流会出现反向，使同步整流变换器工作于强制CCM(Continuous Conduction mode，连续导通模式)，影响同步整流变换器的效率。At present, synchronous rectification converters have been widely used in various fields. Since the freewheeling switching tubes in synchronous rectification converters do not have single-conductivity, the main switching tubes in the synchronous rectification converters are turned off and freewheeling switches. When the tube is turned on, if the load current is small, the inductor current in the synchronous rectification converter will be reversed, so that the synchronous rectification converter operates in a forced CCM (Continuous Conduction Mode), which affects the synchronous rectification converter. effectiveness.
通常，为了提高同步整流变换器的效率，多会在同步整流变换器中设置电感电流过零检测电路，如图1所示，该检测电路主要由比较器CMP_ZERO实现；具体的，当同步整流变换器中，开关管Q1作为主开关管关断、开关管Q2作为续流开关管导通时，比较器CMP_ZERO比较续流开关管Q2漏极电压和源极电压的大小，在电感L电流出现反向时，续流开关管Q2漏极电压大于源极电压，比较器CMP_ZERO翻转，输出高电平信号至驱动电路。驱动电路在接收到比较器CMP_ZERO输出的高电平信号后，产生逻辑信号关断续流开关管Q2，使同步整流变换器工作于DCM(Discontinuous Conduction mode，不连续导通模式)，能够降低续流开关管Q2的功耗损失，提高同步整流变换器的效率。Generally, in order to improve the efficiency of the synchronous rectification converter, an inductor current zero-crossing detection circuit is often provided in the synchronous rectification converter. As shown in FIG. 1, the detection circuit is mainly implemented by a comparator CMP_ZERO; specifically, when synchronous rectification is performed In the device, when the switch tube Q1 is turned off as the main switch tube and the switch tube Q2 is turned on as the freewheel switch tube, the comparator CMP_ZERO compares the magnitude of the drain voltage and the source voltage of the freewheeling switch tube Q2, and the current in the inductor L is reversed. In the forward direction, the drain voltage of the freewheeling switch Q2 is greater than the source voltage, the comparator CMP_ZERO is inverted, and a high level signal is output to the driving circuit. After receiving the high level signal outputted by the comparator CMP_ZERO, the driving circuit generates a logic signal to turn off the freewheeling switch tube Q2, so that the synchronous rectification converter operates in the DCM (Discontinuous Conduction mode), which can reduce the continuation. The power loss of the flow switch tube Q2 increases the efficiency of the synchronous rectifier converter.
然而实际中，由于同步整流变换器的电感电流过零检测电路中比较器失调电压、电路的延时以及工艺偏差的影响，同步整流变换器的电感电流过零检测并不准确，使得同步整流变换器的效率仍然很低。However, in practice, due to the influence of the comparator offset voltage, the delay of the circuit and the process deviation in the inductor current zero-crossing detection circuit of the synchronous rectifier converter, the zero-crossing detection of the inductor current of the synchronous rectifier converter is not accurate, so that the synchronous rectification transformation The efficiency of the device is still very low.
发明内容Summary of the invention
本申请提供一种同步整流变换器的电感电流过零检测电路中比较器的控制方法及控制电路，用以解决同步整流变换器的电感电流过零检测精确度较低的问题。The present invention provides a control method and a control circuit for a comparator in an inductor current zero-crossing detection circuit of a synchronous rectifier converter, which is used to solve the problem that the accuracy of the zero-crossing detection of the synchronous current of the synchronous rectifier converter is low.
本申请提供了一种比较器的控制方法，包括： The application provides a method for controlling a comparator, including:
检测同步整流变换器的续流开关管的体二极管是否导通，以及同步整流变换器的电感电流是否小于等于零；Detecting whether the body diode of the freewheeling switch of the synchronous rectifier converter is turned on, and whether the inductor current of the synchronous rectifier converter is less than or equal to zero;
根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压。According to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than or equal to zero, the synchronous rectification conversion is controlled. The inductor current zero-crossing detects the offset voltage of the comparator in the circuit.
可选的，根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压，具体包括：Optionally, according to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than or equal to zero, Controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter, specifically including:
当同步整流变换器的续流开关管的体二极管未导通、同步整流变换器的电感电流小于等于零时，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压增大。When the body diode of the freewheeling switch of the synchronous rectification converter is not turned on, and the inductor current of the synchronous rectification converter is less than or equal to zero, the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter is increased.
可选的，根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压，具体包括：Optionally, according to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than or equal to zero, Controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter, specifically including:
当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流已过零、同步整流变换器的续流开关管的体二极管导通时，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压减小。When the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current has passed zero and the body diode of the freewheeling switching tube of the synchronous rectifier converter is turned on, the inductor current of the synchronous rectifier converter is controlled. The offset voltage of the comparator in the zero detection circuit is reduced.
可选的，根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压，具体包括：Optionally, according to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than or equal to zero, Controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter, specifically including:
当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流未过零、同步整流变换器的电感电流不小于等于零时，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压不变。When the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current does not zero, and the inductor current of the synchronous rectifier converter is not less than or equal to zero, the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled. The offset voltage of the comparator does not change.
较佳的，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压，具体包括：Preferably, the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled, and specifically includes:
在控制同步整流变换器的电感电流过零检测电路中比较器的失调电压改变时，根据历史数据控制改变幅度。When the offset voltage of the comparator in the inductor current zero-crossing detecting circuit of the synchronous rectification converter is controlled, the magnitude of the change is controlled according to the history data.
本申请还提供了一种比较器的控制电路，包括：The application also provides a control circuit for the comparator, comprising:
体二极管检测单元，用于检测同步整流变换器的续流开关管的体二极管是否导通；a body diode detecting unit, configured to detect whether a body diode of the freewheeling switch tube of the synchronous rectifier converter is turned on;
电感检测单元，用于检测同步整流变换器的电感电流是否小于等于零；An inductance detecting unit, configured to detect whether an inductor current of the synchronous rectifier converter is less than or equal to zero;
控制单元，用于根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否 小于等于零，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压。a control unit, configured to: according to an output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is Less than or equal to zero, the offset current of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled.
可选的，所述控制单元，具体用于：当同步整流变换器的续流开关管的体二极管未导通、同步整流变换器的电感电流小于等于零时，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压增大。Optionally, the control unit is specifically configured to: when the body diode of the freewheeling switch of the synchronous rectifier converter is not turned on, and the inductor current of the synchronous rectifier converter is less than or equal to zero, the inductor current of the synchronous rectifier converter is controlled. The offset voltage of the comparator in the zero detection circuit increases.
可选的，所述控制单元，具体用于：当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流已过零、同步整流变换器的续流开关管的体二极管导通时，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压减小。Optionally, the control unit is specifically configured to: when the output current of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current has crossed zero, the body diode of the freewheeling switch tube of the synchronous rectifier converter When turned on, the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled to decrease.
可选的，所述控制单元，具体用于：当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流未过零、同步整流变换器的电感电流不小于等于零时，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压不变。Optionally, the control unit is specifically configured to: when an output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current does not cross zero, and the inductor current of the synchronous rectifier converter is not less than or equal to zero, The offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled.
较佳的，所述控制单元，具体用于：在控制同步整流变换器的电感电流过零检测电路中比较器的失调电压改变时，根据历史数据控制改变幅度。Preferably, the control unit is specifically configured to: when the offset voltage of the comparator is changed in the inductor current zero-crossing detection circuit of the synchronous rectifier converter, control the change amplitude according to the historical data.
本申请有益效果如下：The beneficial effects of the application are as follows:
本申请实施例提供的方案中，根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零这三个因素来综合判断同步整流变换器的工作状态，进而动态控制同步整流变换器的电感电流过零检测电路中比较器的失调电压，能够减小电路延时以及工艺偏差的影响，提高同步整流变换器的电感电流过零检测电路的检测精度。In the solution provided by the embodiment of the present application, the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and the inductance of the synchronous rectification converter Whether the current is less than or equal to zero is used to comprehensively judge the working state of the synchronous rectifier converter, thereby dynamically controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter, which can reduce the circuit delay and process deviation. The effect is to improve the detection accuracy of the inductor current zero-crossing detection circuit of the synchronous rectifier converter.
附图说明DRAWINGS
图1为现有技术中同步整流变换器的电感电流过零检测电路的结构示意图；1 is a schematic structural view of an inductor current zero-crossing detecting circuit of a synchronous rectification converter in the prior art;
图2为本申请实施例提供的同步整流变换器的电感电流过零检测电路中比较器的控制方法的流程示意图；2 is a schematic flow chart of a method for controlling a comparator in an inductor current zero-crossing detecting circuit of a synchronous rectification converter according to an embodiment of the present disclosure;
图3为本申请实施例提供的同步整流变换器的电感电流过零检测电路中比较器的控制电路的结构示意图；3 is a schematic structural diagram of a control circuit of a comparator in an inductor current zero-crossing detecting circuit of a synchronous rectification converter according to an embodiment of the present application;
图4为本申请实施例提供的同步整流变换器的电感电流过零检测电路中比较器的控制电路的详细结构示意图；4 is a schematic structural diagram of a control circuit of a comparator in an inductor current zero-crossing detecting circuit of a synchronous rectification converter according to an embodiment of the present application;
图5为本申请实施例提供的同步整流变换器的电感电流过零检测电路中比较器的控制电路的控制单元中电压调整子单元的结构示意图之一；5 is a schematic structural diagram of a voltage adjustment subunit in a control unit of a comparator control circuit of an inductor current zero-crossing detection circuit of a synchronous rectification converter according to an embodiment of the present disclosure;
图6为本申请实施例提供的同步整流变换器的电感电流过零检测电路中比较器的控制电路的控制单元中电压调整子单元的结构示意图之二； 6 is a second schematic structural diagram of a voltage adjustment subunit in a control unit of a comparator control circuit of a synchronous current rectifier zero-crossing detection circuit according to an embodiment of the present application;
图7为本申请实施例提供的同步整流变换器的电感电流过零检测电路中比较器的控制电路的控制单元中逻辑控制子单元的工作时序示意图之一；FIG. 7 is a schematic diagram of a working sequence diagram of a logic control subunit in a control unit of a comparator control circuit of a synchronous current rectifier zero-crossing detection circuit according to an embodiment of the present invention; FIG.
图8为本申请实施例提供的同步整流变换器的电感电流过零检测电路中比较器的控制电路的控制单元中逻辑控制子单元的工作时序示意图之二；8 is a second schematic diagram of the operation timing of the logic control subunit in the control unit of the comparator control circuit of the synchronous current rectifier zero-crossing detection circuit of the synchronous rectifier converter according to the embodiment of the present invention;
图9为本申请实施例提供的同步整流变换器的电感电流过零检测电路中比较器的控制电路的控制单元中逻辑控制子单元的工作时序示意图之三；9 is a third schematic diagram of the operation timing of the logic control subunit in the control unit of the comparator control circuit of the synchronous current rectifier zero-crossing detection circuit of the synchronous rectifier converter according to the embodiment of the present invention;
图10为本申请实施例提供的同步整流变换器的电感电流过零检测电路中比较器的控制电路的控制单元中逻辑控制子单元的工作时序示意图之四；10 is a fourth working sequence diagram of a logic control subunit in a control unit of a comparator control circuit of a synchronous current rectifier zero-crossing detection circuit according to an embodiment of the present invention;
图11为本申请实施例提供的同步整流变换器的电感电流过零检测电路中比较器的控制电路的控制单元中逻辑控制子单元的工作时序示意图之五。FIG. 11 is a fifth schematic diagram of the operation timing of the logic control subunit in the control unit of the comparator control circuit of the synchronous current rectifier zero-crossing detection circuit of the synchronous rectifier converter according to the embodiment of the present application.
具体实施方式detailed description
本申请实施例提供了一种比较器的控制方法及控制电路，用以提高同步整流变换器的电感电流过零检测电路的检测精度。以下结合说明书附图对本申请的优选实施例进行说明，应当理解，此处所描述的优选实施例仅用于说明和解释本申请，并不用于限定本申请。并且在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互组合。The embodiment of the present application provides a comparator control method and a control circuit for improving the detection precision of the inductor current zero-crossing detection circuit of the synchronous rectifier converter. The preferred embodiments of the present application are described with reference to the accompanying drawings, and the preferred embodiments described herein are intended to illustrate and explain the invention. And in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.
本申请实施例提供了一种比较器的控制方法，应用于同步整流变换器的电感电流过零检测电路中，该控制方法如图2所示，具体可以包括如下步骤：The embodiment of the present application provides a control method for a comparator, which is applied to an inductor current zero-crossing detection circuit of a synchronous rectifier converter. The control method is as shown in FIG. 2, and specifically includes the following steps:
步骤101、检测同步整流变换器的续流开关管的体二极管是否导通，以及同步整流变换器的电感电流是否小于等于零；Step 101: Detect whether a body diode of a freewheeling switch tube of the synchronous rectifier converter is turned on, and whether an inductor current of the synchronous rectifier converter is less than or equal to zero;
步骤102、根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压。Step 102: According to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than or equal to zero, the control is performed. The offset current of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter.
其中，同步整流变换器的电感电流过零检测电路中比较器用于比较同步整流变换器的续流开关管的漏极电压和源极电压。The comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is used to compare the drain voltage and the source voltage of the freewheeling switching tube of the synchronous rectifier converter.
具体的，步骤102、根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压，具体可以包括：Specifically, in step 102, according to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than Equal to zero, controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter, which may specifically include:
当同步整流变换器的续流开关管的体二极管未导通、同步整流变换器的电感电流小于等于零时，无论同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电 流是否过零，均控制同步整流变换器的电感电流过零检测电路中比较器的失调电压增大；When the body diode of the freewheeling switch of the synchronous rectifier converter is not turned on, and the inductor current of the synchronous rectifier converter is less than or equal to zero, the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates the inductor power Whether the current crosses zero or not, and controls the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter to increase;
当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流已过零、同步整流变换器的续流开关管的体二极管导通时，无论同步整流变换器的电感电流是否小于等于零，均控制同步整流变换器的电感电流过零检测电路中比较器的失调电压减小；When the output signal of the comparator in the inductor current zero-crossing detecting circuit of the synchronous rectification converter indicates that the inductor current has passed zero and the body diode of the freewheeling switching tube of the synchronous rectification converter is turned on, regardless of whether the inductor current of the synchronous rectification converter is If the value is less than or equal to zero, the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled to decrease;
其它情况，例如：当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流未过零、同步整流变换器的电感电流不小于等于零时，无论同步整流变换器的续流开关管的体二极管是否导通，均控制同步整流变换器的电感电流过零检测电路中比较器的失调电压不变。In other cases, for example, when the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current does not zero, and the inductor current of the synchronous rectifier converter is not less than or equal to zero, regardless of the freewheeling of the synchronous rectifier converter Whether the body diode of the switch tube is turned on, both control the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter.
即本申请实施例提供的同步整流变换器的电感电流过零检测电路中比较器的控制方法，根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零这三个因素来综合判断同步整流变换器的工作状态，进而动态控制同步整流变换器的电感电流过零检测电路中比较器的失调电压，能够减小电路延时以及工艺偏差的影响，提高同步整流变换器的电感电流过零检测电路的检测精度，使同步整流变换器中的续流开关管的关断位置更理想。That is, the control method of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter provided by the embodiment of the present application, according to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, and the continuation of the synchronous rectification converter The three factors of whether the body diode of the flow switching tube is turned on and whether the inductor current of the synchronous rectifier converter is less than or equal to zero are comprehensively judged to determine the working state of the synchronous rectifier converter, thereby dynamically controlling the inductor current zero-crossing detecting circuit of the synchronous rectifier converter The offset voltage of the comparator can reduce the influence of circuit delay and process deviation, improve the detection accuracy of the inductor current zero-crossing detection circuit of the synchronous rectifier converter, and make the switch-off position of the freewheeling switch tube in the synchronous rectifier converter more ideal.
具体的，基于同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零这三个因素共有8种排列组合出现：Specifically, based on the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the free-wheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than or equal to zero. A total of 8 combinations of factors appear:
1、当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流未过零、同步整流变换器的续流开关管的体二极管未导通、同步整流变换器的电感电流不小于等于零时，此时，同步整流变换器的工作于CCM，且电感电流未过零，续流开关管未被提前关断，则比较器的失调电压无需调整；1. When the inductor current zero-crossing detection circuit of the synchronous rectifier converter detects that the inductor current does not cross zero, the body diode of the freewheeling switch of the synchronous rectifier converter is not turned on, and the inductor current of the synchronous rectifier converter When not less than or equal to zero, at this time, the synchronous rectification converter operates in CCM, and the inductor current does not cross zero, and the freewheeling switch tube is not turned off in advance, the offset voltage of the comparator does not need to be adjusted;
2、当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流未过零、同步整流变换器的续流开关管的体二极管导通、同步整流变换器的电感电流不小于等于零时，此时，同步整流变换器的工作于CCM，且电感电流未过零，续流开关管未被提前关断，则比较器的失调电压无需调整；2. When the inductor current zero-crossing detection circuit of the synchronous rectifier converter detects that the inductor current does not cross zero, the body diode of the free-wheeling switch of the synchronous rectifier converter is turned on, and the inductor current of the synchronous rectifier converter is not When it is less than or equal to zero, at this time, the synchronous rectification converter operates in CCM, and the inductor current does not cross zero, and the freewheeling switch tube is not turned off in advance, the offset voltage of the comparator does not need to be adjusted;
3、当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流未过零、同步整流变换器的续流开关管的体二极管未导通、同步整流变换器的电感电流小于等于零时，此时，同步整流变换器的工作于CCM，且电感电流已过零，即强制CCM，则比较器的失调电压需要调大； 3. When the inductor current zero-crossing detection circuit of the synchronous rectifier converter detects that the inductor current does not cross zero, the body diode of the freewheeling switch of the synchronous rectifier converter is not turned on, and the inductor current of the synchronous rectifier converter When the value is less than or equal to zero, at this time, the synchronous rectification converter operates in CCM, and the inductor current has passed zero, that is, the CCM is forced, and the offset voltage of the comparator needs to be increased;
4、当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流已过零、同步整流变换器的续流开关管的体二极管未导通、同步整流变换器的电感电流小于等于零时，此时，同步整流变换器的工作于DCM，且电感电流已过零，则比较器的失调电压需要调大；4. When the inductor current zero-crossing detection circuit of the synchronous rectifier converter detects that the inductor current has crossed zero, the body diode of the freewheeling switch of the synchronous rectifier converter is not turned on, and the inductor current of the synchronous rectifier converter When the value is less than or equal to zero, at this time, the synchronous rectification converter operates in DCM, and the inductor current has passed zero, the offset voltage of the comparator needs to be increased;
5、当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流已过零、同步整流变换器的续流开关管的体二极管导通、同步整流变换器的电感电流不小于等于零时，此时，同步整流变换器的工作于CCM，且电感电流未过零，续流开关管被提前关断，则比较器的失调电压需要调小；5. When the inductor current zero-crossing detection circuit of the synchronous rectifier converter detects that the inductor current has passed zero, the body diode of the free-wheeling switch of the synchronous rectifier converter is turned on, and the inductor current of the synchronous rectifier converter is not When the value is less than or equal to zero, at this time, the synchronous rectification converter operates in CCM, and the inductor current does not cross zero, and the freewheeling switch tube is turned off in advance, the offset voltage of the comparator needs to be reduced;
6、当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流已过零、同步整流变换器的续流开关管的体二极管导通、同步整流变换器的电感电流小于等于零时，此时，同步整流变换器的工作于DCM，且电感电流未过零，则比较器的失调电压需要调小；6. When the output current of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current has passed zero, the body diode of the freewheeling switch of the synchronous rectifier converter is turned on, and the inductor current of the synchronous rectifier converter is less than When it is equal to zero, at this time, the synchronous rectification converter operates in DCM, and the inductor current does not cross zero, the offset voltage of the comparator needs to be reduced;
7、当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流未过零、同步整流变换器的续流开关管的体二极管导通、同步整流变换器的电感电流小于等于零时，为误差工作状态，通常不会出现；此时，比较器的失调电压无需调整；7. When the inductor current zero-crossing detection circuit of the synchronous rectifier converter detects that the inductor current does not cross zero, the body diode of the free-wheeling switch of the synchronous rectifier converter is turned on, and the inductor current of the synchronous rectifier converter is less than When it is equal to zero, it is the error working state, usually does not appear; at this time, the offset voltage of the comparator does not need to be adjusted;
8、当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流已过零、同步整流变换器的续流开关管的体二极管未导通、同步整流变换器的电感电流不小于等于零时，为误差工作状态，通常不会出现；此时，比较器的失调电压无需调整。8. When the output current of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current has passed zero, the body diode of the freewheeling switch of the synchronous rectifier converter is not turned on, and the inductor current of the synchronous rectifier converter When it is not less than or equal to zero, it is an error working state, and usually does not appear; at this time, the offset voltage of the comparator does not need to be adjusted.
上述已将同步整流变换器工作中可能出现的状态全部包括，下面将其整理列表，如下表1所示： All of the states that may occur in the operation of the synchronous rectifier converter have been included in the above, and are listed below, as shown in Table 1 below:
Figure PCTCN2017071107-appb-000001
Figure PCTCN2017071107-appb-000001
表1Table 1
较佳的，步骤102中，在控制同步整流变换器的电感电流过零检测电路中比较器的失调电压改变时，可以根据历史数据控制改变幅度。Preferably, in step 102, when the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is changed, the magnitude of the change can be controlled according to the historical data.
基于同一发明构思，根据本申请实施例提供的比较器的控制方法，本申请实施例还提供了一种比较器的控制电路，应用于同步整流变换器的电感电流过零检测电路中，该控制电路，如图3所示，具体可以包括如下单元：According to the same inventive concept, according to the control method of the comparator provided by the embodiment of the present application, the embodiment of the present application further provides a control circuit of the comparator, which is applied to the inductor current zero-crossing detection circuit of the synchronous rectifier converter, and the control The circuit, as shown in FIG. 3, may specifically include the following units:
体二极管检测单元301，用于检测同步整流变换器的续流开关管的体二极管是否导通；The body diode detecting unit 301 is configured to detect whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on;
电感检测单元302，用于检测同步整流变换器的电感电流是否小于等于零；The inductor detecting unit 302 is configured to detect whether the inductor current of the synchronous rectifier converter is less than or equal to zero;
控制单元303，用于根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压。The control unit 303 is configured to: according to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than Equal to zero, controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter.
其中，控制单元303，具体用于：当同步整流变换器的续流开关管的体二极管未导通、同步整流变换器的电感电流小于等于零时，无论同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流是否过零，均控制同步整流变换器的电感电流过零检测电路中比较器的失调电压增大。The control unit 303 is specifically configured to: when the body diode of the freewheeling switch of the synchronous rectifier converter is not turned on, and the inductor current of the synchronous rectifier converter is less than or equal to zero, regardless of the inductor current zero-crossing detection circuit of the synchronous rectifier converter The output signal of the middle comparator indicates whether the inductor current crosses zero, and both control the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter to increase.
进一步的，控制单元303，还具体用于：当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流已过零、同步整流变换器的续流开关管的体二极管导通时，无论同步整流变换器的电感电流是否小于等于零，均控制同步整流变换器的电感电流 过零检测电路中比较器的失调电压减小。Further, the control unit 303 is further configured to: when the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter indicates that the inductor current has passed zero, the body diode guide of the freewheeling switch tube of the synchronous rectification converter When the inductor current of the synchronous rectifier converter is less than or equal to zero, the inductor current of the synchronous rectifier converter is controlled. The offset voltage of the comparator in the zero-crossing detection circuit is reduced.
进一步的，控制单元303，还具体用于：在其它情况，例如：当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流未过零、同步整流变换器的电感电流不小于等于零时，无论同步整流变换器的续流开关管的体二极管是否导通，均控制同步整流变换器的电感电流过零检测电路中比较器的失调电压不变。Further, the control unit 303 is further specifically configured to: in other cases, for example, when the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current does not cross zero, the inductor current of the synchronous rectifier converter When not less than or equal to zero, the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled regardless of whether the body diode of the freewheeling switching tube of the synchronous rectifier converter is turned on.
较佳的，控制单元303，还可以在控制同步整流变换器的电感电流过零检测电路中比较器的失调电压改变时，根据历史数据控制改变幅度。Preferably, the control unit 303 can also control the change amplitude according to the historical data when the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is changed.
实际实施时，可以如图4所示，体二极管检测单元301可以采用比较器CMP_DIO实现，电感检测单元302可以采用比较器CMP_ILN和抗振铃电路实现，控制单元303可以采用逻辑控制子单元、加减计数器和电压调整子单元实现。In actual implementation, as shown in FIG. 4, the body diode detecting unit 301 can be implemented by using a comparator CMP_DIO, the inductor detecting unit 302 can be implemented by using a comparator CMP_ILN and an anti-ringing circuit, and the control unit 303 can adopt a logic control sub-unit, plus Subtract counter and voltage adjustment subunit implementation.
同步整流变换器的电感电流过零检测电路中比较器CMP_ZERO的输出信号ZRDT一方面会输出到驱动电路，参与续流开关管的关断控制，另一方面会输出到逻辑控制子单元，参与同步整流变换器的工作状态的判断。The output signal ZRDT of the comparator CMP_ZERO in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is output to the drive circuit on the one hand, and participates in the turn-off control of the freewheeling switch tube, and is output to the logic control sub-unit on the other hand to participate in the synchronization. The judgment of the operating state of the rectifier converter.
当续流开关管关断时，如果电感电流IL大于零，则续流开关管的体二极管会导通，续流开关管的漏极电压LX为-700mV左右，因此可以将参考电压VREF1取值在0.3V～0.6V范围内。基于此特性可以检测续流开关管的体二极管是否导通，比较器CMP_DIO的输出信号ZDIO表征该检测结果，被输出到逻辑控制子单元。When the freewheeling switch tube is turned off, if the inductor current I L is greater than zero, the body diode of the freewheeling switch tube is turned on, and the drain voltage L X of the freewheeling switch tube is about -700 mV, so the reference voltage VREF1 can be used. The value ranges from 0.3V to 0.6V. Based on this characteristic, it can be detected whether the body diode of the freewheeling switch tube is turned on, and the output signal ZDIO of the comparator CMP_DIO represents the detection result and is output to the logic control subunit.
续流开关管关断后，抗振铃电路打开，如果电感电流小于等于零，在主开关管与续流开关管同时关断的时间内，续流开关管的漏极电压LX最终会上升到大于等于输出电压Vo，因此可以将参考电压VREF2的取值在200mV～Vo范围内。基于此特性可以检测电感电流是否小于等于零，比较器CMP_ILN的输出信号ZILN表征该检测结果，被输出到逻辑控制子单元。After the freewheeling switch tube is turned off, the anti-ringing circuit is turned on. If the inductor current is less than or equal to zero, the drain voltage L X of the freewheeling switch tube will eventually rise to the time when the main switching tube and the freewheeling switching tube are simultaneously turned off. It is greater than or equal to the output voltage Vo, so the value of the reference voltage VREF2 can be in the range of 200 mV to Vo. Based on this characteristic, it can be detected whether the inductor current is less than or equal to zero, and the output signal ZILN of the comparator CMP_ILN characterizes the detection result and is output to the logic control subunit.
逻辑控制子单元用于判断同步整流变换器的工作状态，并将比较器失调电压的控制信号UP(增大)、DN(减小)以及HOLD(保持)输出到加减计数器。The logic control subunit is configured to determine the operating state of the synchronous rectifier converter, and output the control signals UP (increase), DN (decrease), and HOLD (hold) of the comparator offset voltage to the up-down counter.
加减计数器用于累加或累减计数，其计数位数N的多少决定了比较器失调电压调节档位的多少，其输出信号ZR_CL[N-1:0]会输出到电压调整子单元，控制比较器CMP_ZERO的失调电压。The up-down counter is used to accumulate or decrement the count. The number of count bits N determines the number of comparator offset voltage adjustment gears. The output signal ZR_CL[N-1:0] is output to the voltage adjustment sub-unit. The offset voltage of the comparator CMP_ZERO.
驱动电路接收比较器CMP_ZERO的输出信号，驱动主开关管与续流开关管，同时也输出NGATE和PGATE信号到逻辑控制子单元(图4中未示出)，控制逻辑时序。The driving circuit receives the output signal of the comparator CMP_ZERO, drives the main switch tube and the freewheeling switch tube, and also outputs the NGATE and PGATE signals to the logic control sub-unit (not shown in FIG. 4) to control the logic timing.
实际实施时，电压调整子单元可以采用图5所示电路实现，其中译码器将ZR_CL[N-1:0]译码成S0～Sm-1(其中m＝2N)，每一码位对应一个开关；由电阻的分压关系，不同的电 阻上对应不同的电压，因而当打开不同的开关时，通过加法器叠加到续流开关管的漏极电压LX上的电压是不相同的，对应码ZR_CL[N-1:0]越大，叠加的电压越大，对应码ZR_CL[N-1:0]越小，叠加的电压越小。电源地DCGND上也叠加了一个参考电压VREF3，参考电压VREF3的大小等于虚线框中电阻串调节电压范围的一半。In actual implementation, the voltage adjustment subunit can be implemented by the circuit shown in FIG. 5, wherein the decoder decodes ZR_CL[N-1:0] into S0~Sm-1 (where m=2N), and each code bit corresponds to a switch; the voltage divider relationship of the resistors, different resistors corresponding to different voltages, so when the different switches are turned on, the voltage superimposed on the drain voltage L X of the freewheeling switch tube by the adder is different, The larger the corresponding code ZR_CL[N-1:0], the larger the superimposed voltage, and the smaller the corresponding code ZR_CL[N-1:0], the smaller the superimposed voltage. A reference voltage VREF3 is also superimposed on the DCGND of the power supply. The magnitude of the reference voltage VREF3 is equal to half of the voltage regulation range of the resistor string in the dotted line.
上述图5所示电路仅为示例，并不用于限定本申请。本申请实施例提供的同步整流变换器的电感电流过零检测电路中比较器的控制电路中的电压调整子单元还可以采用其它方式实现，例如图6所示，在此不再详述。The circuit shown in FIG. 5 above is merely an example and is not intended to limit the application. The voltage adjustment subunit in the control circuit of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter provided by the embodiment of the present application can also be implemented in other manners, for example, as shown in FIG. 6, and will not be described in detail herein.
下表2中列出了检测周期T内ZDIO、ZILN、ZRDT与UP、DN、HOLD信号之间的关系。The relationship between ZDIO, ZILN, ZRDT and UP, DN, and HOLD signals in the detection period T is listed in Table 2 below.
表2Table 2
其中，“1”表示高电平，“0”表示低电平。Among them, "1" indicates a high level, and "0" indicates a low level.
当同步整流变换器工作于CCM，且电感电流未过零，续流开关管未被提前关断时，图4所示控制电路的工作时序示意图如图7所示。When the synchronous rectification converter operates in the CCM, and the inductor current does not cross zero, and the freewheeling switch tube is not turned off in advance, the operation timing diagram of the control circuit shown in FIG. 4 is as shown in FIG. 7.
当同步整流变换器的工作于CCM，且电感电流已过零，即强制CCM时，图4所示控制电路的工作时序示意图如图8所示。当比较器失调电压设置得过小时，这种情况容易发生。When the synchronous rectification converter operates in CCM and the inductor current has passed zero, that is, CCM is forced, the operation timing diagram of the control circuit shown in FIG. 4 is as shown in FIG. 8. This situation is easy to occur when the comparator offset voltage is set too small.
当同步整流变换器的工作于DCM，且电感电流已过零时，图4所示控制电路的工作时序示意图如图9所示。When the synchronous rectification converter operates in DCM and the inductor current has passed zero, the operational timing diagram of the control circuit shown in FIG. 4 is as shown in FIG.
当同步整流变换器的工作于CCM，且电感电流未过零，续流开关管被提前关断时，图 4所示控制电路的工作时序示意图如图10所示。当比较器失调电压设置得过大时，这种情况容易发生。When the synchronous rectification converter operates in CCM and the inductor current does not cross zero, the freewheeling switch tube is turned off in advance, The working timing diagram of the control circuit shown in FIG. 4 is as shown in FIG. This situation is apt to occur when the comparator offset voltage is set too large.
当同步整流变换器的工作于DCM，且电感电流未过零时，图4所示控制电路的工作时序示意图如图11所示。When the synchronous rectification converter operates in DCM and the inductor current does not cross zero, the operational timing diagram of the control circuit shown in FIG. 4 is as shown in FIG.
综上所述，采用本申请实施例提供的方案，能够提高同步整流变换器的电感电流过零检测电路的检测精度，提高同步整流变换器的工作效率。In summary, with the solution provided by the embodiment of the present application, the detection precision of the inductor current zero-crossing detection circuit of the synchronous rectifier converter can be improved, and the working efficiency of the synchronous rectifier converter can be improved.
显然，本领域的技术人员可以对本申请进行各种改动和变型而不脱离本申请的精神和范围。这样，倘若本申请的这些修改和变型属于本申请权利要求及其等同技术的范围之内，则本申请也意图包含这些改动和变型在内。 It will be apparent to those skilled in the art that various modifications and changes can be made in the present application without departing from the spirit and scope of the application. Thus, it is intended that the present invention cover the modifications and variations of the present invention.

Claims (10)

  1. 一种比较器的控制方法，其特征在于，包括：A control method for a comparator, comprising:
    检测同步整流变换器的续流开关管的体二极管是否导通，以及同步整流变换器的电感电流是否小于等于零；Detecting whether the body diode of the freewheeling switch of the synchronous rectifier converter is turned on, and whether the inductor current of the synchronous rectifier converter is less than or equal to zero;
    根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压。According to the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than or equal to zero, the synchronous rectification conversion is controlled. The inductor current zero-crossing detects the offset voltage of the comparator in the circuit.
  2. 如权利要求1所述的控制方法，其特征在于，根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压，具体包括：The control method according to claim 1, wherein the output signal of the comparator in the inductor current zero-crossing detecting circuit of the synchronous rectification converter, the body diode of the freewheeling switching tube of the synchronous rectification converter are turned on and synchronized. Whether the inductor current of the rectifier converter is less than or equal to zero, and controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter, specifically includes:
    当同步整流变换器的续流开关管的体二极管未导通、同步整流变换器的电感电流小于等于零时，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压增大。When the body diode of the freewheeling switch of the synchronous rectification converter is not turned on, and the inductor current of the synchronous rectification converter is less than or equal to zero, the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter is increased.
  3. 如权利要求1所述的控制方法，其特征在于，根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压，具体包括：The control method according to claim 1, wherein the output signal of the comparator in the inductor current zero-crossing detecting circuit of the synchronous rectification converter, the body diode of the freewheeling switching tube of the synchronous rectification converter are turned on and synchronized. Whether the inductor current of the rectifier converter is less than or equal to zero, and controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter, specifically includes:
    当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流已过零、同步整流变换器的续流开关管的体二极管导通时，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压减小。When the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current has passed zero and the body diode of the freewheeling switching tube of the synchronous rectifier converter is turned on, the inductor current of the synchronous rectifier converter is controlled. The offset voltage of the comparator in the zero detection circuit is reduced.
  4. 如权利要求1所述的控制方法，其特征在于，根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压，具体包括：The control method according to claim 1, wherein the output signal of the comparator in the inductor current zero-crossing detecting circuit of the synchronous rectification converter, the body diode of the freewheeling switching tube of the synchronous rectification converter are turned on and synchronized. Whether the inductor current of the rectifier converter is less than or equal to zero, and controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter, specifically includes:
    当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流未过零、同步整流变换器的电感电流不小于等于零时，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压不变。When the output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter indicates that the inductor current does not zero, and the inductor current of the synchronous rectifier converter is not less than or equal to zero, the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled. The offset voltage of the comparator does not change.
  5. 如权利要求1-4任一所述的控制方法，其特征在于，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压，具体包括：The control method according to any one of claims 1 to 4, wherein controlling the offset voltage of the comparator in the inductor current zero-crossing detecting circuit of the synchronous rectification converter comprises:
    在控制同步整流变换器的电感电流过零检测电路中比较器的失调电压改变时，根据历 史数据控制改变幅度。When the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is changed, according to the calendar Historical data controls the extent of the change.
  6. 一种比较器的控制电路，其特征在于，包括：A control circuit for a comparator, comprising:
    体二极管检测单元，用于检测同步整流变换器的续流开关管的体二极管是否导通；a body diode detecting unit, configured to detect whether a body diode of the freewheeling switch tube of the synchronous rectifier converter is turned on;
    电感检测单元，用于检测同步整流变换器的电感电流是否小于等于零；An inductance detecting unit, configured to detect whether an inductor current of the synchronous rectifier converter is less than or equal to zero;
    控制单元，用于根据同步整流变换器的电感电流过零检测电路中比较器的输出信号、同步整流变换器的续流开关管的体二极管是否导通以及同步整流变换器的电感电流是否小于等于零，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压。a control unit, configured to: according to an output signal of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectification converter, whether the body diode of the freewheeling switch tube of the synchronous rectification converter is turned on, and whether the inductor current of the synchronous rectification converter is less than or equal to zero And controlling the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter.
  7. 如权利要求6所述的控制电路，其特征在于，所述控制单元，具体用于：当同步整流变换器的续流开关管的体二极管未导通、同步整流变换器的电感电流小于等于零时，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压增大。The control circuit according to claim 6, wherein the control unit is specifically configured to: when the body diode of the freewheeling switch of the synchronous rectification converter is not turned on, and the inductor current of the synchronous rectification converter is less than or equal to zero The offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is increased.
  8. 如权利要求6所述的控制电路，其特征在于，所述控制单元，具体用于：当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流已过零、同步整流变换器的续流开关管的体二极管导通时，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压减小。The control circuit according to claim 6, wherein the control unit is specifically configured to: when the output current of the comparator in the inductor current zero-crossing detecting circuit of the synchronous rectification converter indicates that the inductor current has passed zero, synchronous rectification When the body diode of the freewheeling switch of the converter is turned on, the offset voltage of the comparator in the inductor current zero-crossing detecting circuit of the synchronous rectifier converter is controlled to decrease.
  9. 如权利要求6所述的控制电路，其特征在于，所述控制单元，具体用于：当同步整流变换器的电感电流过零检测电路中比较器的输出信号指示电感电流未过零、同步整流变换器的电感电流不小于等于零时，控制同步整流变换器的电感电流过零检测电路中比较器的失调电压不变。The control circuit according to claim 6, wherein the control unit is specifically configured to: when an inductor current zero-crossing detecting circuit of the synchronous rectification converter detects an output current of the comparator, the inductor current does not cross zero, and synchronous rectification When the inductor current of the converter is not less than or equal to zero, the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter is controlled.
  10. 如权利要求6-9任一所述的控制电路，其特征在于，所述控制单元，具体用于在控制同步整流变换器的电感电流过零检测电路中比较器的失调电压改变时，根据历史数据控制改变幅度。 The control circuit according to any one of claims 6-9, wherein the control unit is specifically configured to control the offset voltage of the comparator in the inductor current zero-crossing detection circuit of the synchronous rectifier converter according to history. Data control changes the magnitude.
PCT/CN2017/071107 2016-02-24 2017-01-13 Method of controlling comparator and control circuit WO2017143884A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201610102859.2A CN107124112B (en) 2016-02-24 2016-02-24 Control method and control circuit of comparator
CN201610102859.2 2016-02-24

Publications (1)

Publication Number Publication Date
WO2017143884A1 true WO2017143884A1 (en) 2017-08-31

Family

ID=59684686

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2017/071107 WO2017143884A1 (en) 2016-02-24 2017-01-13 Method of controlling comparator and control circuit

Country Status (2)

Country Link
CN (1) CN107124112B (en)
WO (1) WO2017143884A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113970664A (en) * 2020-07-24 2022-01-25 圣邦微电子（北京）股份有限公司 High-precision current sampling circuit, constant current control circuit and sampling method
US11456666B2 (en) * 2019-02-13 2022-09-27 Nuvoton Technology Corporation Zero current detection system used in switching regulator comprising an inductor

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107834829B (en) * 2017-11-20 2019-08-02 电子科技大学 A kind of adaptive reflux comparator
CN112838755B (en) * 2021-01-28 2022-04-08 上海空间电源研究所 Current backflow prevention circuit for BUCK converter

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1470968A (en) * 2002-06-13 2004-01-28 ��ķ�ɷ����޹�˾ Switch device driving device and DC/DC current transformer
CN101056055A (en) * 2006-04-14 2007-10-17 圆创科技股份有限公司 Reverse current prevention circuit capable of self-correcting reference benchmark
CN102735914A (en) * 2012-05-10 2012-10-17 成都芯源系统有限公司 Synchronous rectification circuit and zero-crossing detection method
CN103616556A (en) * 2013-11-22 2014-03-05 矽力杰半导体技术(杭州)有限公司 Zero-cross detection circuit and detection method used for synchronous buck converter
US20140191744A1 (en) * 2013-01-07 2014-07-10 Samsung Electronics Co., Ltd. Switching regulator and comparator-based zero current detection method used by the switching regulator

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW200906056A (en) * 2007-07-27 2009-02-01 Niko Semiconductor Co Ltd Pulse width modulation controller applied to a switch-mode regulator
CN103176497B (en) * 2013-03-06 2014-09-24 山东力创赢芯集成电路有限公司 Comparator offset voltage compensation circuit and compensation method
CN104467364B (en) * 2014-12-15 2017-03-01 矽力杰半导体技术(杭州)有限公司 A kind of zero cross detection circuit and Switching Power Supply

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1470968A (en) * 2002-06-13 2004-01-28 ��ķ�ɷ����޹�˾ Switch device driving device and DC/DC current transformer
CN101056055A (en) * 2006-04-14 2007-10-17 圆创科技股份有限公司 Reverse current prevention circuit capable of self-correcting reference benchmark
CN102735914A (en) * 2012-05-10 2012-10-17 成都芯源系统有限公司 Synchronous rectification circuit and zero-crossing detection method
US20140191744A1 (en) * 2013-01-07 2014-07-10 Samsung Electronics Co., Ltd. Switching regulator and comparator-based zero current detection method used by the switching regulator
CN103616556A (en) * 2013-11-22 2014-03-05 矽力杰半导体技术(杭州)有限公司 Zero-cross detection circuit and detection method used for synchronous buck converter

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11456666B2 (en) * 2019-02-13 2022-09-27 Nuvoton Technology Corporation Zero current detection system used in switching regulator comprising an inductor
CN113970664A (en) * 2020-07-24 2022-01-25 圣邦微电子（北京）股份有限公司 High-precision current sampling circuit, constant current control circuit and sampling method
CN113970664B (en) * 2020-07-24 2024-04-12 圣邦微电子（北京）股份有限公司 High-precision current sampling circuit, constant-current control circuit and sampling method

Also Published As

Publication number Publication date
CN107124112B (en) 2020-02-07
CN107124112A (en) 2017-09-01

Similar Documents

Publication Publication Date Title
WO2017143884A1 (en) Method of controlling comparator and control circuit
US10097076B2 (en) Control circuit, control method and flyback converter
CN108306513B (en) Turn-off control circuit of synchronous rectifier tube and synchronous rectifier control circuit
US8675374B2 (en) Auto-optimization circuits and methods for cyclical electronic systems
US7888925B2 (en) Load current compensation in synchronous power converters
CN107086793B (en) Dynamic compensation control circuit for synchronous rectification power converter
US7683594B2 (en) Intelligent dead time control
US8823335B2 (en) Switching power supply apparatus
WO2017157250A1 (en) Totem-pole bridgeless power factor correction circuit control method and apparatus
US9502976B2 (en) Power supply circuit and control method for the same
WO2009081561A1 (en) Power conversion device, switch device and method for controlling power conversion device
JP2012070490A (en) Bridgeless power factor improvement converter
US20230246538A1 (en) Zero-voltage-switching control circuit, control method and switching power supply
JPWO2005119893A1 (en) PWM cycloconverter and control method thereof
WO2017000474A1 (en) Pre-bias on-and-off circuit, and circuit and method for pre-biasing multi-cascade converter
US20170025969A1 (en) Synchronous rectifier phase control to improve load efficiency
CN111585440B (en) Control system and method of active clamp flyback converter
JP2016039705A (en) Electric power converter
WO2019111504A1 (en) Switching power supply device control method, switching power supply device, and control circuit for same
WO2018087960A1 (en) Power factor compensation power supply device and led lighting device
JP6589667B2 (en) Bridgeless PFC converter
JP7200901B2 (en) power supply
JP6358861B2 (en) Insulation resistance measuring device
JP2009290812A (en) Dead time control circuit
Meng et al. Real time zero current detection with low quiescent current for synchronous DC-DC converter

Legal Events

Date Code Title Description
NENP Non-entry into the national phase

Ref country code: DE

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17755713

Country of ref document: EP

Kind code of ref document: A1

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 112(1) EPC (EPO FORM 1205A DATED 13/02/2019)

122 Ep: pct application non-entry in european phase

Ref document number: 17755713

Country of ref document: EP

Kind code of ref document: A1