WO2021057450A1 - 开关变换器及其低压启动电路 - Google Patents

开关变换器及其低压启动电路 Download PDF

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WO2021057450A1
WO2021057450A1 PCT/CN2020/113553 CN2020113553W WO2021057450A1 WO 2021057450 A1 WO2021057450 A1 WO 2021057450A1 CN 2020113553 W CN2020113553 W CN 2020113553W WO 2021057450 A1 WO2021057450 A1 WO 2021057450A1
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Prior art keywords
voltage
transistor
substrate
low
switch tube
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PCT/CN2020/113553
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English (en)
French (fr)
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许晶
闫守宝
于翔
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圣邦微电子（北京）股份有限公司
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Priority to US17/763,744 priority Critical patent/US11929667B2/en
Publication of WO2021057450A1 publication Critical patent/WO2021057450A1/zh

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/36—Means for starting or stopping converters
    • 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
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
    • H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
    • H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • 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
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H02M1/0006—Arrangements for supplying an adequate voltage to the control circuit of converters
    • 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 invention relates to the technical field of switching power supplies, and more specifically, to a switching converter and a low-voltage starting circuit thereof.
  • the switching converter is used to convert the input voltage into a predetermined output voltage to supply the load.
  • the existing switching converter includes a main switching tube, a synchronous switching tube, an inductor, and a driving circuit.
  • the driving circuit is used to control the on and off states of the main switch tube and the synchronous switch tube, so that the inductor alternately stores and supplies electric energy, thereby generating output voltage and/or output current.
  • Fig. 1 shows a schematic structural diagram of a switching converter in the prior art.
  • the switching converter adopts Boost topology.
  • the switching converter 100 includes an inductor L1, a main switching tube Mn, a synchronous switching tube Mp, an output capacitor Cout, and a driving circuit 110.
  • the inductor L1 and the main switch tube Mn are connected in series between the DC input voltage Vin and ground.
  • the first end of the synchronous switch tube Mp is connected to the node between the inductor L1 and the main switch tube Mn, and the second end is connected to the DC output voltage Vout. Terminal, the output capacitor Cout is connected between the second terminal of the synchronous switch tube Mp and the ground.
  • the driving circuit 110 is used to control the turn-on and turn-off of the main switch tube Mn and the synchronous switch tube Mp.
  • the main switching tube Mn is turned on, the synchronous switching tube Mp is turned off, and the inductor L1 starts to store electric energy.
  • the main switch M1 is turned off, the synchronous switch tube Mp is turned on, and the inductor L1 starts to supply electric energy to the output capacitor Cout, so that the DC output voltage Vout gradually rises.
  • the existing switching converter 100 has the following problem: Affected by the threshold voltage and parasitic capacitance of the main switching tube Mn, the starting voltage of the switching converter 100 is limited. When the DC input voltage Vin is low, due to the The driving voltage comes from the DC input voltage Vin, which will cause the main switching tube Mn to fail to conduct normally and the switching converter 100 to fail to start normally.
  • the object of the present invention is to provide a switching converter and its low-voltage start-up circuit, which reduces the conduction threshold of the main switch tube, realizes the normal conduction of the main switch tube when the input voltage is low, and improves the performance of the switching converter. Low-voltage starting capability.
  • a low-voltage startup circuit of a switching converter the switching converter includes a main switching tube, a synchronous switching tube, an inductor, and an output capacitor, wherein the low-voltage startup circuit includes: The comparator is used to compare the input voltage with the reference voltage, and obtain a voltage detection signal according to the comparison result; the substrate voltage control module is used to adjust the substrate voltage of the main switch tube according to the voltage detection signal, wherein, when When the voltage detection signal indicates that the input voltage is less than/equal to the reference voltage, the substrate voltage control module increases the substrate voltage of the main switch tube.
  • the substrate voltage control module includes: a first transistor, a first resistor, and a second transistor connected in series between the input voltage and ground, and the middle of the first resistor and the second transistor is connected in series.
  • the node is connected to the substrate of the main switch tube, the gates of the first transistor and the second transistor receive the voltage detection signal, and the first transistor is used to respond to the input when it is turned on.
  • the voltage charges the substrate of the main switch tube, and the second transistor is used to discharge the substrate of the main switch tube when it is turned on.
  • the substrate voltage control module further includes: a third transistor, a second resistor, and a fourth transistor connected in series between the input voltage and ground, and the second resistor and the fourth transistor are connected in series.
  • the intermediate node is connected to the substrate of the first transistor, and the gates of the third transistor and the fourth transistor receive the inverted signal of the voltage detection signal, and the third transistor is used for turning on The substrate of the first transistor is charged according to the input voltage, and the fourth transistor is used to discharge the substrate of the first transistor when it is turned on.
  • the first transistor and the fourth transistor are turned on, and when the voltage detection signal indicates that the input voltage is greater than the reference voltage.
  • the second transistor and the third transistor are turned on.
  • the first transistor and the third transistor are P-type field effect transistors
  • the second transistor and the fourth transistor are N-type field effect transistors.
  • the low-voltage startup circuit further includes a diode connected between the substrate and the source of the main switch tube.
  • the low-voltage startup circuit further includes an operational amplifier, the inverting input terminal is connected to the substrate of the main switch tube, the non-inverting input terminal is used to receive a reference voltage, and the output terminal is connected to the inverting input terminal , wherein the operational amplifier is used to clamp the substrate voltage of the main switch tube according to the reference voltage.
  • the reference voltage is equal to the difference between the turn-on threshold of the diode and a predetermined voltage.
  • a switching converter including: a main switch tube, a synchronous switch tube, an inductor, and an output capacitor, and the above-mentioned low-voltage startup circuit.
  • the low-voltage startup circuit compares the input voltage with a reference voltage, and adjusts the substrate voltage of the main switch tube according to the comparison result.
  • the low-voltage start-up circuit increases the substrate voltage of the main switch tube, and then lowers the turn-on threshold of the main switch tube to realize the normal conduction of the main switch tube when the input voltage is low, and Low-voltage start-up capability of the switching converter.
  • the low-voltage start-up circuit of the switching converter further includes an operational amplifier, which clamps the substrate voltage of the main switch tube to a certain range to avoid the latch-up effect caused when the substrate voltage of the main switch tube is too large.
  • Figure 1 shows a schematic structural diagram of a switching converter according to the prior art
  • Fig. 2 shows a schematic structural diagram of a switching converter according to an embodiment of the present invention.
  • circuit refers to a conductive loop formed by at least one element or sub-circuit through electrical or electromagnetic connection.
  • an element or circuit When an element or circuit is said to be “connected” to another element or an element/circuit is “connected” between two nodes, it can be directly coupled or connected to the other element or there may be intermediate elements, and the connection between the elements may be It is physical, logical, or a combination of them.
  • an element when referred to as being “directly coupled to” or “directly connected to” another element, it means that there are no intervening elements between the two.
  • the switch tube is a transistor that operates in a switching mode to provide a current path, and includes one selected from a bipolar transistor or a field effect transistor.
  • the first terminal and the second terminal of the switch tube are respectively the high potential terminal and the low potential terminal on the current path, and the control terminal is used for receiving the driving signal to control the on and off of the switch tube.
  • Fig. 2 shows a schematic circuit diagram of a switching converter according to an embodiment of the present invention.
  • the switching converter 200 includes a low-voltage startup circuit 210 and a power stage circuit integrated in the same integrated circuit chip.
  • the low-voltage startup circuit 210 includes a substrate voltage control module 211, a comparator 212, an inverter 213, and an operational amplifier 214.
  • the power stage circuit includes discrete components such as a main switch tube Mn, a synchronous switch tube Mp, an inductor L1, and an output capacitor Cout, and a load.
  • the switching converter 200 is used to provide a DC output voltage Vout for a load.
  • the inductor L1 of the power stage circuit and the main switching tube Mn are connected in series between the DC input voltage Vin and ground.
  • the first end of the synchronous switching tube Mp is connected to the node between the inductor L1 and the main switching tube Mn.
  • the two ends are connected to the DC output voltage Vout end, and the output capacitor Cout is connected between the second end of the synchronous switch tube Mp and the ground.
  • the turn-on and turn-off of the main switch tube Mn and the synchronous switch tube Mp are controlled by the driving signal TG, and the driving signal TG is, for example, a duty cycle signal.
  • the main switching tube Mn for example, uses an N-type field effect transistor, and the synchronous switching tube Mp, for example, a P-type field effect transistor.
  • the main switching tube Mn and the synchronous switching tube Mp are turned on and off alternately, so that the inductor L1 Alternately store electrical energy and supply electrical energy.
  • the switching converter 200 starts to work, the main switch tube Mn is turned on, the synchronous switch tube Mp is turned off, and the inductor L1 starts to store electric energy.
  • the main switch M1 is turned off, the synchronous switch tube Mp is turned on, and the inductor L1 starts to supply electric energy to the output capacitor Cout, so that the DC output voltage Vout gradually rises.
  • the low-voltage startup circuit 210 is used to increase the substrate voltage of the main switching tube Mn when the input voltage Vin is less than the preset reference voltage, and then reduce the turn-on threshold of the main switching tube Mn, and then the main switching tube Mn when the input voltage Vin is small It can be turned on normally, which improves the low-voltage starting ability of the switching converter 200.
  • the comparator 212 compares the input voltage Vin with a reference voltage V1, and obtains the voltage detection signal VA according to the comparison result.
  • the inverter 213 is used to provide the inverted signal VB of the voltage detection signal VA to the substrate voltage control module 211.
  • the substrate voltage control module 211 adjusts the substrate voltage of the main switch tube Mn according to the level state of the voltage detection signal VA and its inverted signal VB. Wherein, when the voltage detection signal indicates that the input voltage Vin is less than/equal to the reference voltage V1, the substrate voltage control module 211 increases the substrate voltage of the main switch tube Mn.
  • the substrate voltage control module 211 includes transistors M1-M4 and resistors R1 and R2.
  • the transistor M1 and the transistor M3 are, for example, P-type field effect transistors, and the transistor M2 and the transistor M4 are, for example, N-type field effect transistors.
  • the transistor M1, the resistor R1, and the transistor M2 are sequentially connected in series between the input voltage Vin and the ground.
  • the intermediate node of the resistor R1 and the transistor M2 is connected to the substrate of the main switch tube Mn.
  • the gates of the transistor M1 and the transistor M2 receive the voltage detection signal VA.
  • the transistor M1 is used to charge the substrate of the main switch tube Mn according to the input voltage Vin when it is turned on, so as to reduce the turn-on threshold of the main switch tube Mn.
  • the transistor M2 is used for discharging the substrate of the main switching tube Mn when it is turned on, and pulling the substrate voltage of the main switching tube Mn down to the ground.
  • the transistor M3, the resistor R2, and the transistor M4 are sequentially connected in series between the input voltage Vin and the ground.
  • the intermediate node of the resistor R2 and the transistor M3 is connected to the substrate of the transistor M1.
  • the gates of the transistor M3 and the transistor M4 receive the inverted signal VB of the voltage detection signal VA.
  • the transistor M3 is used to charge the substrate of the transistor M1 according to the input voltage Vin when it is turned on.
  • the transistor M4 is used to discharge the substrate of the transistor M1 when it is turned on, and pull the substrate voltage of the transistor M1 down to the ground.
  • the voltage detection signal VA is low and its inverted signal VB is high, the transistor M3 is turned off, the transistor M4 is turned on, and the substrate voltage of the transistor M1 is pulled If it is low, then the turn-on threshold of the transistor M1 is reduced.
  • the resistor R2 mainly acts as a current limiter. Then the transistor M1 is turned on, the transistor M2 is turned off, the substrate voltage of the main switch Mn is pulled up, and the turn-on threshold of the main switch Mn is reduced. At this time, the resistor R1 mainly acts as a current limiter. Finally, the main switching tube Mn is normally turned on and off when the input voltage Vin is low, and the low-voltage starting ability of the switching converter 200 is improved.
  • the output of the comparator 212 is inverted, the voltage detection signal VA is inverted to a high level, and the inverted signal VB of the voltage detection signal VA is inverted to a low level.
  • the transistor M2 and the transistor M3 are turned on, the transistors M1 and M4 are turned off, the substrate voltage of the transistor M1 is equal to the input voltage Vin, the substrate of the main switch tube Mn is grounded, and the switching converter 200 can work normally.
  • the low-voltage start-up circuit 210 also includes a diode D1 located between the substrate and the source of the main switching tube Mn.
  • a diode D1 located between the substrate and the source of the main switching tube Mn.
  • this embodiment further includes an operational amplifier 214, which is used to clamp the substrate voltage of the main switch tube Mn to a certain voltage range.
  • the inverting input terminal of the operational amplifier 214 is connected to the substrate of the main switch tube Mn to receive the substrate voltage
  • the non-inverting input terminal is used to receive a reference voltage V2
  • the output terminal is connected to the inverting input terminal.
  • the reference voltage V2 is equal to the difference between the turn-on threshold of the diode D1 and a preset voltage (for example, 0.2V).
  • the operational amplifier 214 is used to clamp the substrate voltage of the main switch tube according to the reference voltage V2 so that it is always lower than the reference voltage V2.
  • the low-voltage start-up circuit compares the input voltage with a reference voltage, and adjusts the substrate voltage of the main switch tube according to the comparison result.
  • the low-voltage start-up circuit increases the substrate voltage of the main switch tube, and then lowers the turn-on threshold of the main switch tube to realize the normal conduction of the main switch tube when the input voltage is low, and Low-voltage start-up capability of the switching converter.
  • the low-voltage start-up circuit of the switching converter further includes an operational amplifier, which clamps the substrate voltage of the main switch tube to a certain range to avoid the latch-up effect caused when the substrate voltage of the main switch tube is too large.
  • the present invention can also be applied to the control method of the switching converter.
  • the switching converter adopting the low-voltage control method when the input voltage is less than/equal to the reference voltage, the low-voltage startup circuit increases the substrate voltage of the main switching tube, Then the turn-on threshold of the main switch tube is lowered to realize the normal turn-on of the main switch tube when the input voltage is low, and the low-voltage start-up capability of the switching converter is improved.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

一种开关变换器（200）及其低压启动电路（210），低压启动电路（210）包括比较器（212）和衬底电压控制模块（211），比较器（212）用于将输入电压（Vin）与基准电压（V1）进行比较，根据比较结果得到电压检测信号（VA），衬底电压控制模块（211）用于根据电压检测信号（VA）调节主开关管（Mn）的衬底电压，其中，当电压检测信号（VA）表征输入电压（Vin）小于/等于基准电压（V1）时，衬底电压控制模块（211）增大主开关管（Mn）的衬底电压，继而降低主开关管（Mn）的导通阈值，实现主开关管（Mn）在输入电压（Vin）较低时的正常导通，提高开关变换器（200）的低压启动能力。

Description

开关变换器及其低压启动电路
本申请要求了2019年9月25日提交的、申请号为201910910267.7、发明名称为“开关变换器及其低压启动电路”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。
技术领域
本发明涉及开关电源技术领域，更具体地，涉及一种开关变换器及其低压启动电路。
背景技术
开关变换器用于将输入电压转换成预定的输出电压供给负载。现有的开关变换器包括主开关管、同步开关管、电感和驱动电路。驱动电路用于控制主开关管和同步开关管的导通和关断状态，使得电感交替储存电能和供给电能，从而产生输出电压和/或输出电流。
如图1示出了现有技术的一种开关变换器的结构示意图。该开关变换器采用Boost拓扑。开关变换器100包括电感L1、主开关管Mn、同步开关管Mp、输出电容Cout以及驱动电路110。电感L1和主开关管Mn串联连接在直流输入电压Vin和地之间，同步开关管Mp的第一端连接至电感L1和主开关管Mn之间的节点，第二端连接至直流输出电压Vout端，输出电容Cout连接在同步开关管Mp的第二端和地之间。驱动电路110用于控制主开关管Mn和同步开关管Mp的导通和关断。开关变换器100工作时，主开关管Mn导通，同步开关管Mp关断，电感L1开始储存电能。然后主开关M1关断，同步开关管Mp导通，电感L1开始向输出电容Cout供给电能，使得直流输出电压Vout逐渐升高。
现有的开关变换器100具有以下问题：受主开关管Mn的阈值电压以及寄生电容的影响，开关变换器100的启动电压受到限制，当直流输入电压Vin较低时，由于驱动电路110中的驱动电压来自直流输入电压Vin，会导致主开关管Mn无法正常导通，开关变换器100无法正常启动。
发明内容
鉴于上述问题，本发明的目的在于提供一种开关变换器及其低压启动电路，降低主开关管的导通阈值，实现主开关管在输入电压较低时的正常导通，提高开关变换器的低压启动能力。
根据本发明实施例的第一方面，提供了一种开关变换器的低压启动电路，所述开关变换器包括主开关管、同步开关管、电感以及输出电容，其中，所述低压启动电路包括：比较器，用于将输入电压与基准电压进行比较，根据比较结果得到电压检测信号；衬底电压控制模块，用于根据所述电压检测信号调节所述主开关管的衬底电压，其中，当所述电压检测信号表征所述 输入电压小于/等于所述基准电压时，所述衬底电压控制模块增大所述主开关管的衬底电压。
优选地，所述衬底电压控制模块包括：依次串联连接于所述输入电压与地之间的第一晶体管、第一电阻以及第二晶体管，所述第一电阻和所述第二晶体管的中间节点连接至所述主开关管的衬底，所述第一晶体管和所述第二晶体管的栅极接收所述电压检测信号，其中，所述第一晶体管用于在导通时根据所述输入电压对所述主开关管的衬底进行充电，所述第二晶体管用于在导通时对所述主开关管的衬底进行放电。
优选地，所述衬底电压控制模块还包括：依次串联连接于所述输入电压与地之间的第三晶体管、第二电阻以及第四晶体管，所述第二电阻和所述第四晶体管的中间节点连接至所述第一晶体管的衬底，所述第三晶体管和所述第四晶体管的栅极接收所述电压检测信号的反相信号，其中，所述第三晶体管用于在导通时根据所述输入电压对所述第一晶体管的衬底进行充电，所述第四晶体管用于在导通时对所述第一晶体管的衬底进行放电。
优选地，当所述电压检测信号表征所述输入电压小于/等于所述基准电压时，所述第一晶体管和所述第四晶体管导通，当所述电压检测信号表征所述输入电压大于所述基准电压时，所述第二晶体管和所述第三晶体管导通。
优选地，所述第一晶体管和所述第三晶体管为P型场效应晶体管，所述第二晶体管和所述第四晶体管为N型场效应晶体管。
优选地，所述低压启动电路还包括连接于所述主开关管的衬底和源极之间的二极管。
优选地，所述低压启动电路还包括：运算放大器，反相输入端连接至所述主开关管的衬底，正相输入端用于接收一参考电压，输出端与所述反相输入端连接，其中，所述运算放大器用于根据所述参考电压钳位所述主开关管的衬底电压。
优选地，所述参考电压等于所述二极管的导通阈值与一预设电压之差。
根据本发明实施例的第二方面，提供了一种开关变换器，包括：主开关管、同步开关管、电感以及输出电容，以及上述的低压启动电路。
本发明实施例的开关变换器及其低压启动电路，低压启动电路将输入电压与一基准电压进行比较，根据比较结果调节主开关管的衬底电压。当输入电压小于/等于该基准电压时，低压启动电路增大主开关管的衬底电压，继而降低主开关管的导通阈值，实现主开关管在输入电压较低时的正常导通，提高开关变换器的低压启动能力。
进一步的，开关变换器的低压启动电路还包括运算放大器，运算放大器将主开关管的衬底电压钳位至一定的范围内，避免当主开关管的衬底电压过大引起的闩锁效应。
附图说明
通过以下参照附图对本发明实施例的描述，本发明的上述以及其他目的、特征和优点将更为清楚，在附图中：
图1示出根据现有技术的一种开关变换器的结构示意图；
图2示出根据本发明实施例的开关变换器的结构示意图。
具体实施方式
以下将参照附图更详细地描述本发明的各种实施例。在各个附图中，相同的元件采用相同或类似的附图标记来表示。为了清楚起见，附图中的各个部分没有按比例绘制。
应当理解，在以下的描述中，“电路”是指由至少一个元件或子电路通过电气连接或电磁连接构成的导电回路。当称元件或电路“连接到”另一元件或称元件/电路“连接在”两个节点之间时，它可以直接耦合或连接到另一元件或者可以存在中间元件，元件之间的连接可以是物理上的、逻辑上的、或者其结合。相反，当称元件“直接耦合到”或“直接连接到”另一元件时，意味着两者不存在中间元件。
在本申请中，开关管是工作开关模式以提供电流路径的晶体管，包括选自双极晶体管或场效应晶体管的一种。开关管的第一端和第二端分别是电流路径上的高电位端和低电位端，控制端用于接收驱动信号以控制开关管的导通和关断。
下面结合附图和实施例对本发明进一步说明。
图2示出根据本发明实施例的开关变换器的电路示意图。该开关变换器200包括集成在同一集成电路芯片中的低压启动电路210和功率级电路。低压启动电路210包括衬底电压控制模块211、比较器212、反相器213、以及运算放大器214。功率级电路包括主开关管Mn、同步开关管Mp、电感L1和输出电容Cout等分立元件，以及负载。
该开关变换器200用于为负载提供直流输出电压Vout。参照图2，功率级电路的电感L1和主开关管Mn串联连接在直流输入电压Vin和地之间，同步开关管Mp的第一端连接至电感L1和主开关管Mn之间的节点，第二端连接至直流输出电压Vout端，输出电容Cout连接在同步开关管Mp的第二端和地之间。主开关管Mn和同步开关管Mp的导通和关断受控于驱动信号TG，驱动信号TG例如为占空比信号。主开关管Mn例如采用N型场效应晶体管，同步开关管Mp例如采用P型场效应晶体管，在每个开关周期中，主开关管Mn和同步开关管Mp交替导通和关断，使得电感L1交替储存电能和供给电能。开关变换器200开始工作时，主开关管Mn导通，同步开关管Mp关断，电感L1开始储存电能。然后主开关M1关断，同步开关管Mp导通，电感L1开始向输出电容Cout供给电能，使得直流输出电压Vout逐渐升高。
低压启动电路210用于在输入电压Vin小于预设基准电压时增大主开关管Mn的衬底电压，继 而减小主开关管Mn的导通阈值，继而在输入电压Vin较小时主开关管Mn可以正常导通，提高了开关变换器200的低压启动能力。
具体地，比较器212将输入电压Vin与一基准电压V1进行比较，根据比较结果得到电压检测信号VA。反相器213用于向衬底电压控制模块211提供电压检测信号VA的反相信号VB。衬底电压控制模块211根据电压检测信号VA及其反相信号VB的电平状态调节主开关管Mn的衬底电压。其中，当电压检测信号表征输入电压Vin小于/等于基准电压V1时，衬底电压控制模块211增大主开关管Mn的衬底电压。
在一种非限制性的实施例中，衬底电压控制模块211包括晶体管M1-M4以及电阻R1和电阻R2。晶体管M1和晶体管M3例如为P型场效应晶体管，晶体管M2和晶体管M4例如为N型场效应晶体管。
晶体管M1、电阻R1和晶体管M2依次串联连接在输入电压Vin和地之间。电阻R1和晶体管M2的中间节点连接至主开关管Mn的衬底。晶体管M1和晶体管M2的栅极接收电压检测信号VA。晶体管M1用于在导通时根据所述输入电压Vin对主开关管Mn的衬底进行充电，以减小主开关管Mn的导通阈值。晶体管M2用于在导通时对主开关管Mn的衬底进行放电，将主开关管Mn的衬底电压拉低至地。
晶体管M3、电阻R2和晶体管M4依次串联连接在输入电压Vin和地之间。电阻R2和晶体管M3的中间节点连接至晶体管M1的衬底。晶体管M3和晶体管M4的栅极接收电压检测信号VA的反相信号VB。晶体管M3用于在导通时根据所述输入电压Vin对晶体管M1的衬底进行充电。晶体管M4用于在导通时对晶体管M1的衬底进行放电，将晶体管M1的衬底电压拉低至地。
当输入电压Vin小于/等于基准电压V1时，电压检测信号VA为低电平，其的反相信号VB为高电平，晶体管M3关断，晶体管M4导通，晶体管M1的衬底电压被拉低，继而晶体管M1的导通阈值降低，此时电阻R2主要起到限流的作用。继而晶体管M1导通，晶体管M2关断，主开关管Mn的衬底电压被拉高，主开关管Mn的导通阈值降低，此时电阻R1主要起到限流的作用。最终实现主开关管Mn在输入电压Vin较低时的正常导通和关断，提高开关变换器200的低压启动能力。
当输入电压Vin大于基准电压V1时，比较器212输出翻转，电压检测信号VA翻转为高电平，电压检测信号VA的反相信号VB翻转为低电平。晶体管M2和晶体管M3导通，晶体管M1和M4关断，晶体管M1的衬底电压等于输入电压Vin，主开关管Mn的衬底接地，开关变换器200可正常工作。
进一步的，低压启动电路210还包括位于主开关管Mn的衬底和源极之间的二极管D1，当主开关管Mn的衬底电压大于二极管D1的导通阈值时，主开关管Mn的寄生体二极管就会导通，引起闩锁效应。因此本实施例还包括运算放大器214，运算放大器214用于将主开关管Mn的衬底电 压钳位至一定的电压范围内。具体的，运算放大器214的反相输入端连接至主开关管Mn的衬底以接收衬底电压，正相输入端用于接收一参考电压V2，输出端与所述反相输入端连接。参考电压V2等于二极管D1的导通阈值与一预设电压(例如0.2V)之差，运算放大器214用于根据参考电压V2钳位所述主开关管的衬底电压，使其始终小于参考电压V2。
综上所述，在本发明的开关变换器中，低压启动电路将输入电压与一基准电压进行比较，根据比较结果调节主开关管的衬底电压。当输入电压小于/等于该基准电压时，低压启动电路增大主开关管的衬底电压，继而降低主开关管的导通阈值，实现主开关管在输入电压较低时的正常导通，提高开关变换器的低压启动能力。
进一步的，开关变换器的低压启动电路还包括运算放大器，运算放大器将主开关管的衬底电压钳位至一定的范围内，避免当主开关管的衬底电压过大引起的闩锁效应。
以上详细说明了本发明实施例的开关变换器的实现原理。同理，本发明还可以运用到开关变换器的控制方法，对于采用低压控制方法的开关变换器，当输入电压小于/等于该基准电压时，低压启动电路增大主开关管的衬底电压，继而降低主开关管的导通阈值，实现主开关管在输入电压较低时的正常导通，提高开关变换器的低压启动能力。
依照本发明的实施例如上文，这些实施例并没有详尽叙述所有的细节，也不限制该发明仅为的具体实施例。显然，根据以上描述，可作很多的修改和变化。本说明书选取并具体描述这些实施例，是为了更好地解释本发明的原理和实际应用，从而使所属技术领域技术人员能很好地利用本发明以及在本发明基础上的修改使用。本发明的保护范围应当以本发明权利要求所界定的范围为准。

Claims (9)

  1. 一种开关变换器的低压启动电路，所述开关变换器包括主开关管、同步开关管、电感以及输出电容，其中，所述低压启动电路包括：
    比较器，用于将输入电压与基准电压进行比较，根据比较结果得到电压检测信号；
    衬底电压控制模块，用于根据所述电压检测信号调节所述主开关管的衬底电压，
    其中，当所述电压检测信号表征所述输入电压小于/等于所述基准电压时，所述衬底电压控制模块增大所述主开关管的衬底电压。
  2. 根据权利要求1所述的低压启动电路，其特征在于，所述衬底电压控制模块包括：
    依次串联连接于所述输入电压与地之间的第一晶体管、第一电阻以及第二晶体管，所述第一电阻和所述第二晶体管的中间节点连接至所述主开关管的衬底，
    所述第一晶体管和所述第二晶体管的栅极接收所述电压检测信号，
    其中，所述第一晶体管用于在导通时根据所述输入电压对所述主开关管的衬底进行充电，所述第二晶体管用于在导通时对所述主开关管的衬底进行放电。
  3. 根据权利要求2所述的低压启动电路，其特征在于，所述衬底电压控制模块还包括：
    依次串联连接于所述输入电压与地之间的第三晶体管、第二电阻以及第四晶体管，所述第二电阻和所述第四晶体管的中间节点连接至所述第一晶体管的衬底，
    所述第三晶体管和所述第四晶体管的栅极接收所述电压检测信号的反相信号，
    其中，所述第三晶体管用于在导通时根据所述输入电压对所述第一晶体管的衬底进行充电，所述第四晶体管用于在导通时对所述第一晶体管的衬底进行放电。
  4. 根据权利要求3所述的低压启动电路，其特征在于，当所述电压检测信号表征所述输入电压小于/等于所述基准电压时，所述第一晶体管和所述第四晶体管导通，
    当所述电压检测信号表征所述输入电压大于所述基准电压时，所述第二晶体管和所述第三晶体管导通。
  5. 根据权利要求3所述的低压启动电路，其特征在于，所述第一晶体管和所述第三晶体管为P型场效应晶体管，所述第二晶体管和所述第四晶体管为N型场效应晶体管。
  6. 根据权利要求1所述的低压启动电路，其特征在于，还包括连接于所述主开关管的衬底和源极之间的二极管。
  7. 根据权利要求6所述的低压启动电路，其特征在于，还包括：
    运算放大器，反相输入端连接至所述主开关管的衬底，正相输入端用于接收一参考电压，输出端与所述反相输入端连接，
    其中，所述运算放大器用于根据所述参考电压钳位所述主开关管的衬底电压。
  8. 根据权利要求7所述的低压启动电路，其特征在于，所述参考电压等于所述二极管的导通阈值与一预设电压之差。
  9. 一种开关变换器，包括：
    主开关管、同步开关管、电感以及输出电容；以及
    权利要求1-8任一项所述的低压启动电路。
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1312493A (zh) * 2000-02-07 2001-09-12 精工电子有限公司 半导体集成电路
US20030011949A1 (en) * 2001-07-13 2003-01-16 Industrial Technology Institute Dual-triggered electrostatic discharge protection circuit
CN1980025A (zh) * 2005-12-08 2007-06-13 富士通株式会社 升压型dc－dc变换器及其控制方法
CN101505094A (zh) * 2009-03-05 2009-08-12 浙江大学 一种便携式设备的电源模块
CN108400704A (zh) * 2018-05-09 2018-08-14 无锡鸿恩泰科技有限公司 升压型dc-dc超低压冷启动电路
CN110098832A (zh) * 2019-04-30 2019-08-06 中国科学院上海微***与信息技术研究所 超低电压启动双路输出的dcdc转换电路及其实现方法

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7504876B1 (en) * 2006-06-28 2009-03-17 Cypress Semiconductor Corporation Substrate bias feedback scheme to reduce chip leakage power
US7816974B2 (en) * 2008-04-04 2010-10-19 Panasonic Corporation Semiconductor integrated circuit device
CN101340084B (zh) * 2008-08-12 2012-09-05 北京中星微电子有限公司 放电过流保护恢复驱动电路、电池保护电路及***
CN104079157B (zh) * 2014-06-19 2016-08-24 南京微盟电子有限公司 一种同步升压dc-dc转换器的超低压启动电路
US9710006B2 (en) * 2014-07-25 2017-07-18 Mie Fujitsu Semiconductor Limited Power up body bias circuits and methods
US11283347B2 (en) * 2015-07-15 2022-03-22 Mitsubishi Electric Corporation Control circuit for supplying VCC
TWI631450B (zh) * 2017-05-19 2018-08-01 新唐科技股份有限公司 基體偏壓產生電路

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1312493A (zh) * 2000-02-07 2001-09-12 精工电子有限公司 半导体集成电路
US20030011949A1 (en) * 2001-07-13 2003-01-16 Industrial Technology Institute Dual-triggered electrostatic discharge protection circuit
CN1980025A (zh) * 2005-12-08 2007-06-13 富士通株式会社 升压型dc－dc变换器及其控制方法
CN101505094A (zh) * 2009-03-05 2009-08-12 浙江大学 一种便携式设备的电源模块
CN108400704A (zh) * 2018-05-09 2018-08-14 无锡鸿恩泰科技有限公司 升压型dc-dc超低压冷启动电路
CN110098832A (zh) * 2019-04-30 2019-08-06 中国科学院上海微***与信息技术研究所 超低电压启动双路输出的dcdc转换电路及其实现方法

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