WO2019161711A1 - 一种低导通压降的启动电路 - Google Patents

一种低导通压降的启动电路 Download PDF

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Publication number
WO2019161711A1
WO2019161711A1 PCT/CN2018/125387 CN2018125387W WO2019161711A1 WO 2019161711 A1 WO2019161711 A1 WO 2019161711A1 CN 2018125387 W CN2018125387 W CN 2018125387W WO 2019161711 A1 WO2019161711 A1 WO 2019161711A1
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Prior art keywords
voltage
circuit
input
vin
zener diode
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PCT/CN2018/125387
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English (en)
French (fr)
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郑典清
冯刚
李树佳
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广州金升阳科技有限公司
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Publication of WO2019161711A1 publication Critical patent/WO2019161711A1/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
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback 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
    • H02M1/0048—Circuits or arrangements for reducing losses
    • 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 invention relates to a starting circuit, in particular to a starting circuit with a low conduction voltage drop.
  • the startup circuit is widely used in the field of switching power supplies.
  • switching power supply products whether it is a primary power supply (AC-DC converter) or a secondary power supply (DC-DC converter)
  • AC-DC converter primary power supply
  • DC-DC converter secondary power supply
  • the IC supplies power to drive the switch on and off by controlling the operation of the circuit, controlling the inductive device to periodically transfer energy.
  • a two-stage power supply circuit (shown in Figure 1) can be used.
  • the first stage circuit clamps the wide input voltage limit to a lower voltage value, and the second stage circuit boosts the front stage voltage through a boost circuit (such as a BOOST circuit). Pressing to the normal operating voltage of the control circuit or control IC enables the switching power supply system to start working.
  • the input supply voltage of the second-stage boosting circuit is lowered, resulting in the second-stage boosting circuit not working properly, and finally, at a low input voltage, It can supply power to the control IC normally.
  • the boost circuit starts to work, and the power supply voltage of the control circuit or the control IC is established, but the circuit operates at low voltage.
  • the tube Q1 works in the amplification area, and the voltage drop across the three-stage tube Q1 and the resistor R2 is large, which reduces the voltage value of Vcc under low voltage, which causes the second-stage boosting circuit to fail to work normally, so that the switching power supply system is lower in Vin. It is difficult to start. With other types of voltage regulator circuits or voltage clamp circuits, there is also the problem of excessive pressure drop at low pressure.
  • the current limited voltage switching power supply startup circuit in the industry is limited to: using a two-stage power supply circuit scheme or a single-stage power supply circuit scheme, the first-stage voltage clamp circuit will have a low-voltage input and output voltage difference.
  • the problem that the boost circuit or the latter control circuit cannot be started cannot meet the starting voltage range from extremely low voltage to high voltage.
  • the present invention provides a low-conduction voltage drop start-up circuit capable of real-time detection of an input voltage.
  • the N-MOS transistor When an input voltage is detected to be lower than a set voltage value, the N-MOS transistor is turned on, so that the start-up circuit is The voltage difference between the output voltage and the input voltage is extremely low, which ensures that the starting voltage of the booster circuit of the latter stage basically follows the input voltage; when the input voltage is detected to be higher than the set voltage value, the voltage limiting circuit works, and the output voltage of the starting circuit is limited.
  • the stage boost circuit operates within the input voltage range.
  • the invention itself has extremely low loss.
  • the loss of the driving circuit itself is low, and because the N-MOS tube is used, the N-MOS tube is saturated and turned on during low voltage operation, and the on-resistance of the starting circuit is extremely low.
  • the voltage limiting circuit can adopt a voltage regulation or voltage limiting circuit that satisfies the low loss, which not only ensures the normal operation of the starting circuit under high input voltage, but also reduces the loss of the starting circuit operation.
  • the low conduction voltage drop starting circuit of the invention comprises a voltage limiting circuit, an N-MOS tube and a driving circuit; the input end of the driving circuit is connected with an input voltage Vin, and the input voltage Vin is subjected to voltage sampling.
  • a control voltage Vg is generated, the control voltage Vg is output to the gate of the N-MOS transistor, the drain of the N-MOS transistor is connected to the input voltage Vin, and the source of the N-MOS transistor is connected to the output terminal of the startup circuit, which is the latter stage.
  • Circuit power supply; the input terminal and the output terminal of the voltage limiting circuit are respectively connected to the drain and the source of the N-MOS transistor;
  • the driving circuit is provided with a determining voltage interval.
  • the N-MOS transistor When the input voltage Vin is smaller than the minimum value of the driving circuit determining voltage interval, the N-MOS transistor is turned on, and the voltage limiting circuit is short-circuited by N. - The source of the MOS tube is extremely powered by the latter stage circuit;
  • the N-MOS transistor and the voltage limiting circuit are both turned on, and the source of the N-MOS transistor and the output of the voltage limiting circuit are common. Powering the rear stage circuit;
  • the N-MOS transistor When the input voltage Vin is greater than the maximum value of the drive circuit determination voltage interval, the N-MOS transistor is turned off, and the output terminal of the voltage limiting circuit supplies power to the subsequent stage circuit.
  • the voltage limiting circuit is a voltage clamping circuit that converts the input voltage Vin into a stable output voltage range, or a voltage stabilization circuit that converts the input voltage Vin into a fixed output voltage value.
  • the voltage stabilizing circuit comprises a second resistor, a third resistor, a first NPN transistor, a first capacitor and a second Zener diode; the second resistor is connected to the input voltage Vin and the first NPN transistor Between the collectors, the third resistor is connected between the input voltage Vin and the base of the first NPN transistor; the base of the first NPN transistor is connected to the cathode of the second Zener diode, The emitter of an NPN transistor is connected to the output terminal VDD of the driving circuit; the anode of the second Zener diode is connected to the ground; and the first capacitor is connected between the output terminal VDD of the driving circuit and the ground.
  • the driving circuit comprises a first resistor and a first Zener diode, one end of the first resistor is connected to the input voltage Vin, and the other end of the first resistor is opposite to the cathode of the first Zener diode Connected, and the connection point serves as the output of the drive circuit to output the control voltage Vg, the anode of the first Zener diode and the ground.
  • the voltage regulator of the first Zener diode is smaller than the voltage regulator of the second Zener diode.
  • the driving circuit determines that the minimum value of the voltage interval is the voltage regulation value of the first Zener diode, and the driving circuit determines that the maximum value of the voltage interval is the voltage regulation value of the first Zener diode and the N-MOS The sum of the threshold voltage values of the tubes.
  • the present invention has the following remarkable effects:
  • the invention adopts an N-MOS tube to control the output voltage of the starting circuit at low voltage, thereby ensuring that the output voltage of the starting circuit is substantially consistent with the input voltage when the voltage is low, and satisfies the power supply requirement of the low voltage stepping circuit of the latter stage.
  • the circuit structure of the invention adopts a voltage limiting circuit composed of a voltage regulator circuit or a clamp circuit with a wide input voltage range, thereby ensuring that the output voltage of the startup circuit is not high when the high voltage input is high, and satisfies the input of the high voltage input circuit of the latter stage. voltage range.
  • Figure 1 is a block diagram of a conventional wide input range start-up circuit that satisfies the low-voltage input
  • Figure 2 is a schematic diagram of a conventional voltage clamping circuit
  • Figure 4 is a schematic diagram of a first embodiment of the present invention.
  • Figure 5 is a schematic diagram of a second embodiment of the present invention.
  • Figure 6 is a schematic diagram of the application of the first embodiment of the present invention.
  • Figure 7 is a schematic diagram of the application of the second embodiment of the present invention.
  • FIG. 3 shows a block diagram of the connection following the initial technical solution described above.
  • Figure 3 shows a block diagram of the connection following the initial technical solution described above.
  • the external power supply device works normally. When the input voltage is within the voltage interval of the drive circuit, the voltage difference between the output voltage of the startup circuit and the input voltage gradually increases with the increase of the input voltage.
  • the external power supply device works normally.
  • the startup voltage output voltage is stabilized at a voltage value or stabilized in an output voltage range, regardless of the change of the input voltage.
  • the voltage limiting circuit, the N-MOS transistor and the driving circuit of the present invention the input end of the driving circuit is connected to the input voltage Vin, and the input voltage Vin is subjected to voltage sampling to generate a control voltage Vg, and the control voltage Vg is output to the N-MOS tube.
  • the gate, the drain of the N-MOS transistor is connected to the input voltage Vin, and the source of the N-MOS transistor is connected to the subsequent stage circuit to supply power to the subsequent stage circuit; the input end and the output end of the voltage limiting circuit are respectively connected to the N-MOS tube Drain and source.
  • the N-MOS transistor TR1 selects a depletion type N-MOS transistor, and is turned on when the Vgs voltage is greater than a certain negative voltage value VT.
  • the voltage limiting circuit is a voltage clamping circuit comprising a constant current limiting chip IC1 and a first capacitor C1.
  • the IC1 has the following characteristics: when the output voltage VDD is lower than the set voltage value, the output voltage VDD follows the input voltage Vin when the output When the voltage is higher than the limit voltage value, the output voltage VDD is limited to a voltage range lower than the set voltage value.
  • the driving circuit includes a first resistor R1 and a first Zener diode Z1.
  • the input end of the first chip IC1 is connected to Vin, the output end VDD of IC1 is connected to the rear stage circuit, and the ground end of IC1 is grounded; the D pole of the N-MOS tube TR1 is connected with Vin, TR1
  • the S pole is connected to the output terminal VDD of the IC1 and is commonly connected to the rear stage circuit.
  • the G pole of the TR1 is connected to the cathode of the first Zener diode Z1; one end of the first resistor R1 is connected to Vin, and the other end is connected to Vin.
  • the cathode of the first Zener diode Z1 is connected, and the connection point serves as an output terminal of the driving circuit to output a control voltage Vg, an anode of the Z1 and a ground; the first capacitor C1 is connected to the output terminal VDD of the IC1 and the ground. between.
  • the Zener diode Z1 When the input voltage does not reach the regulation value of the Zener diode Z1, the Zener diode Z1 is in the off state, and the input voltage Vin charges the G, S capacitor and the capacitor C1 of the N-MOS transistor TR1 through the resistor R1, so that the N-MOS tube
  • the voltage of the G pole of TRI1 to GND is equal to the input voltage Vin
  • the voltage of the G pole of the N-MOS transistor TR1 is greater than the voltage of the S pole
  • the N-MOS transistor TR1 is turned on, so that the output voltage of the starting circuit and the input voltage have almost no pressure difference.
  • the driving circuit When the input voltage gradually rises to be greater than the voltage regulation value of the Zener diode Z1 and is less than the voltage value of the Zener value of the Zener diode Z1 and the absolute value of the threshold voltage value VT of the N-MOS transistor TR1, the driving circuit The output signal Vg voltage value is stabilized in the voltage regulator diode Z1, the N-MOS transistor enters the amplification region, and the current between Vin and VDD is provided by the N-MOS transistor and the IC1. During the slow rise of the Vin, the startup circuit The voltage difference between the output voltages VDD and Vin increases slowly as the N-MOS transistor enters the amplification region.
  • the input voltage Vin exceeds the maximum value of the voltage interval of the driving circuit, that is, the input voltage Vin is greater than the voltage value of the Zener diode Z1 and the threshold voltage VT of the N-MOS transistor TR1, the N-MOS tube Entering the cut-off area, the current between Vin and VDD is only provided by IC1.
  • the output voltage of VDD is determined directly by the regulation characteristic of IC1, and the output voltage is stabilized within the output voltage limit of IC1.
  • the voltage limiting circuit is a voltage stabilizing circuit comprising a second resistor R2, a third resistor R3, a first NPN transistor Q1, a first capacitor C2 and a second Zener diode Z2.
  • the second resistor R2 is connected between the input voltage Vin and the C pole of the first NPN transistor Q1, and the third resistor R3 is connected between the input voltage Vin and the B pole of the first NPN transistor Q1;
  • the B pole of the first NPN transistor Q1 is connected to the cathode of the second Zener diode Z2, the E pole is connected to the output terminal VDD of the driving circuit; the anode of the second Zener diode Z2 is connected to the ground GND;
  • the first capacitor C1 is connected between the output terminal VDD of the driving circuit and the ground GND.
  • the voltage regulator of the first Zener diode Z1 needs to be smaller than the voltage regulator of the second Zener diode Z2.
  • the first Zener diode Z1 selects a Zener diode of 5.1V
  • the second Zener diode Z2 selects a Zener diode of 12V.
  • the Zener diode Z1 When the input voltage does not reach the regulation value of the Zener diode Z1, the Zener diode Z1 is in the off state, and the input voltage Vin charges the G, S capacitor and the capacitor C1 of the N-MOS transistor TR1 through the resistor R1, so that the N-MOS tube
  • the voltage of the G pole of TRI1 to GND is equal to the input voltage Vin
  • the voltage of the G pole of the N-MOS transistor TR1 is greater than the voltage of the S pole
  • the N-MOS transistor TR1 is turned on, so that the output voltage of the starting circuit and the input voltage have almost no pressure difference.
  • the drive is driven.
  • the output voltage of the circuit Vg is stabilized at the voltage regulator Z1, the N-MOS transistor enters the amplification region, and the current between Vin and VDD is linearly stabilized by the N-MOS transistor and R2, R3, Q1 and Z2.
  • the voltage circuit is provided together.
  • the voltage difference between the output voltages VDD and Vin of the startup circuit follows the N-MOS transistor to enter the amplification region and slowly increases.
  • the input voltage Vin exceeds the maximum value of the voltage interval of the driving circuit, that is, the input voltage Vin is greater than the voltage value of the Zener diode Z1 and the threshold voltage VT of the N-MOS transistor TR1, the N-MOS tube Entering the cut-off area, the current between Vin and VDD is only provided by the linear regulator circuit composed of R2, R3, Q1 and Z2.
  • the output voltage of the startup circuit is directly regulated by the linear regulator circuit composed of R2, R3, Q1 and Z2. The characteristics are determined, and the output voltage is stabilized at the voltage regulator of the Zener diode Z1 minus the body diode voltage drop of the B and E of the three-stage transistor Q1.

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Abstract

一种低导通压降的启动电路，能够对输入电压（Vin）进行实时检测，当检测到输入电压（Vin）低于设定电压值时，N-MOS管（TR1）导通，使得启动电路的输出电压（VDD）与输入电压（Vin）的压差极低，保障后级升压电路启动电压基本跟随输入电压（Vin）；当检测到输入电压（Vin）高于设定电压值时，电压限制电路工作，将启动电路输出电压（VDD）限制在后级电路的工作输入电压范围内。

Description

一种低导通压降的启动电路 技术领域
本发明涉及一种启动电路，特别涉及一种低导通压降的启动电路。
背景技术
启动电路广泛应用于开关电源领域。开关电源产品中，无论一次电源(AC-DC变换器)或者二次电源(DC-DC变换器)，都需要从输入端获取能量，并提供一个相对稳定的供电电压为后级控制电路或者控制IC供电，从而通过控制电路工作来驱动开关通断，控制感性器件周期性地传递能量。
一般开关电源中，为解决输入电压低于控制电路或者控制IC最小启动电压时，控制电路或者控制IC因无法获得足够高的供电电压而不能够正常状态，造成对应的开关电源无法开机的问题，可使用两级供电电路(如图1结构)，第一级电路将宽输入电压限制钳位到一个较低的电压值，第二级电路通过升压电路(如BOOST电路)将前级电压升压到符合控制电路或控制IC工作的正常工作电压，使得开关电源系统能够启动工作。但是由于电压钳位电路本身输入和输出端的压降较大，使得第二级升压电路的输入供电电压降低，导致第二级升压电路不能够正常工作，最终使得在低输入电压时，不能够为控制IC正常供电。
传统电压钳位电路方案如图2所示(负载为后级升压电路)，电路工作原理为：产品通电瞬间，三级管Q1导通，三级管Q1的发射极电流迅速向电容C2充电，当电容C2电压(也即启动电路的输出正端提供给控制IC的供电端Vcc的电压)爬升至稳压二极管D1的稳压值减去三级管Q1的基极与发射极导通压降时，Vcc电压将稳定不再增加，在Vcc电压达到升压电路工作电压时，升压电路开始工作，建立起后级控制电路或者控制IC的供电电压，但是电路在低压工作时，三级管Q1工作在放大区，三级管Q1及电阻R2上压降较大，降低了低压下Vcc的电压值，导致第二级升压电路不能够正常工作，使得开关电源系统在Vin较低的时候难以启动。用其他类型的稳压电路或者电压钳位电路，也会出现低压下压差过大的问题。
综上所述，目前行业内宽电压范围开关电源启动电路的局限在：使用两级供电电路方案或单级供电电路方案的产品，第一级电压钳位电路会出现低压下输入 输出压差过大，使得升压电路或后级控制电路无法启动的问题，无法满足从极低电压到高电压的启动电压范围。
发明内容
有鉴如此，本发明提出一种低导通压降的启动电路，能够对输入电压进行实时检测，当检测到输入电压低于设定电压值时，N-MOS管导通，使得启动电路的输出电压与输入电压的压差极低，保障后级升压电路启动电压基本跟随输入电压；当检测到输入电压高于设定电压值时，电压限制电路工作，将启动电路输出电压限制在后级升压电路的工作输入电压范围内。
本发明本身损耗极低，当输入电压为低电压时，驱动电路本身损耗较低，同时因为采用N-MOS管，在低压工作时N-MOS管饱和导通，启动电路的导通电阻极低；在高压工作时，电压限制电路可采用满足损耗较低的稳压或限压电路，既保障了高输入电压下启动电路的正常工作，又减小了启动电路工作的损耗。
本发明所述的一种低导通压降的启动电路，包括电压限制电路、N-MOS管和驱动电路；所述的驱动电路的输入端连接输入电压Vin，对输入电压Vin进行电压采样后产生控制电压Vg，所述控制电压Vg输出给N-MOS管的栅极，N-MOS管的漏极连接输入电压Vin，N-MOS管的源极连接到启动电路的输出端，为后级电路供电；电压限制电路的输入端和输出端分别连接在N-MOS管的漏极和源极；
所述的驱动电路设有判断电压区间，当所述的输入电压Vin小于驱动电路判断电压区间的最小值时，所述的N-MOS管导通，将所述的电压限制电路短路，由N-MOS管的源极为后级电路供电；
当所述的输入电压Vin在驱动电路判断电压区间内时，所述的N-MOS管和所述的电压限制电路都导通，由N-MOS管的源极和电压限制电路的输出端共同为后级电路供电；
当所述的输入电压Vin大于驱动电路判断电压区间的最大值时，所述的N-MOS管关断，由所述的电压限制电路的输出端为后级电路供电。
优选的，所述的电压限制电路是将输入电压Vin转换为稳定的输出电压范围的电压钳位电路，或者是将输入电压Vin转换为固定的输出电压值的稳压电路。
优选的，所述的电压钳位电路包括第一芯片，所述第一芯片的输入端连接输入电压Vin，所述第一芯片的接地端接地，所述第一芯片的输出端连接N-MOS管 的源极。
优选的，所述的稳压电路包括第二电阻、第三电阻、第一NPN三极管、第一电容和第二稳压二极管；所述的第二电阻连接于输入电压Vin和第一NPN三极管的集电极之间，所述的第三电阻连接于输入电压Vin和第一NPN三极管的基极之间；所述的第一NPN三极管的基极连接所述的第二稳压二极管的阴极，第一NPN三极管的发射极连接驱动电路的输出端VDD；所述的第二稳压二极管的阳极连接地；所述的第一电容连接于驱动电路的输出端VDD与地之间。
优选的，所述的驱动电路包括第一电阻和第一稳压二极管，所述的第一电阻的一端连接于输入电压Vin，第一电阻的另一端与所述的第一稳压二极管的阴极相连，并且连接点作为驱动电路的输出端输出控制电压Vg，第一稳压二极管的阳极与接地。
优选的，所述第一稳压二极管的稳压值小于第二稳压二极管的稳压值。
优选的，所述的驱动电路判断电压区间的最小值为第一稳压二极管的稳压值，所述的驱动电路判断电压区间的最大值为第一稳压二极管的稳压值与N-MOS管的门限电压值之和。
与现有技术相比，本发明具有如下的显著效果：
1、本发明采用N-MOS管来控制低压时启动电路的输出电压，从而保障了低压时启动电路输出电压与输入电压基本一致，满足了后级升压电路低压下的供电需求。
2、本发明电路结构采用了宽输入电压范围的稳压电路或者钳位电路组成的电压限制电路，从而保障了高压输入时启动电路输出电压不过高，满足了后级升压电路高压下的输入电压范围。
3、本发明本身损耗极低，采用低损耗的恒流限压芯片组成的电压限制电路，驱动电路的电压采样损耗也较小，不会由于过流装置本身电路特性增大电路损耗。
附图说明
图1为传统的满足低压输入的宽输入范围启动电路的原理框图；
图2为传统的电压钳位电路原理图；
图3为本发明的原理框图；
图4为本发明第一实施例的原理图；
图5为本发明第二实施例的原理图；
图6为本发明第一实施例的应用原理图；
图7为本发明第二实施例的应用原理图。
具体实施方式
图3示出了原理框图，遵循上述初始的技术方案的连接关系。先分点阐述一下本发明具有的3个工作状态：
1、外部供电装置正常工作，输入电压小于驱动电路判断电压区间的最小值时，启动电路的输出电压与输入电压几乎无压差。
2、外部供电装置正常工作，输入电压在驱动电路判断电压区间内时，启动电路的输出电压与输入电压的压差随输入电压的增大缓慢增大。
3、外部供电装置正常工作，输入电压超过驱动电路判断电压区间的最大值时，启动电压输出电压稳定在一个电压值或稳定在一个输出电压范围，与输入电压的变化无关。
第一实施例
本发明的电压限制电路、N-MOS管和驱动电路，驱动电路的输入端连接输入电压Vin，对输入电压Vin进行电压采样后产生控制电压Vg，所述控制电压Vg输出给N-MOS管的栅极，N-MOS管的漏极连接输入电压Vin，N-MOS管的源极连接到后级电路，为后级电路供电；电压限制电路的输入端和输出端分别连接在N-MOS管的漏极和源极。
针对每个电路模块，结合附图4采用以下具体的电路对以上3个工作状态进行具体说明如下：
N-MOS管TR1选择耗尽型N-MOS管，在Vgs电压大于某一负电压值VT即可导通。
电压限制电路是一个电压钳位电路，包括恒流限压芯片IC1和第一电容C1，IC1具有如下特性：当输出电压VDD低于设定电压值时，输出电压VDD跟随输入电压Vin，当输出电压高于限制电压值时，输出电压VDD限定在低于设定电压值的一个电压范围内。
驱动电路包括第一电阻R1和第一稳压二极管Z1。
所述的第一芯片IC1的输入端与Vin相连接，IC1的输出端VDD与后级电路 相连接,IC1接地端接地；所述的N-MOS管TR1的D极与Vin相连接，TR1的S极连接IC1的输出端VDD并且共同连接后级电路，TR1的G极与所述的第一稳压二极管Z1的阴极相连接；所述的第一电阻R1的一端连接于Vin，另一端与所述的第一稳压二极管Z1的阴极相连，并且连接点作为驱动电路的输出端输出控制电压Vg，Z1的阳极与接地；所述的第一电容C1连接于IC1的输出端VDD与地之间。
下面结合图4对本发明的工作过程说明如下：
工作状态1供电装置正常工作，输入电压小于驱动电路判断电压区间的最小值时，启动电路输出电压与输入电压几乎无压差：
当输入电压未达到稳压二极管Z1的稳压值时，稳压二极管Z1于截止状态，输入电压Vin通过电阻R1对N-MOS管TR1的G、S电容和电容C1充电，使得N-MOS管TR1的G极对GND的电压等于输入电压Vin，N-MOS管TR1的G极电压大于S极电压，N-MOS管TR1导通，使得启动电路的输出电压与输入电压几乎无压差。
工作状态2供电装置正常工作，输入电压在驱动电路判断电压区间内时，启动电路输出电压与输入电压的压差随输入电压的增大缓慢增大：
当输入电压逐渐升高到大于稳压二极管Z1的稳压值，且小于稳压二极管Z1的稳压值与N-MOS管TR1的门限电压值VT的绝对值相加的电压值时，驱动电路的输出信号Vg电压值稳定在稳压二极管Z1的稳压值，N-MOS管进入放大区，Vin与VDD之间电流由N-MOS管与IC1共同提供，Vin缓慢上升的过程中，启动电路输出电压VDD与Vin之间的压差跟随N-MOS管进入放大区而缓慢增大。
工作状态3供电装置正常工作，输入电压超过驱动电路判断电压区间的最大值时，启动电路输出电压稳定在一个电压值或稳定在一个输出电压范围，与输入电压的变化无关：
当输入电压Vin超过驱动电路判断电压区间的最大值时，即输入电压Vin大于稳压二极管Z1的稳压值与N-MOS管TR1的门限电压值VT相加的电压值时，N-MOS管进入截止区，Vin与VDD之间电流只由IC1提供，启动电路输出电压VDD直接由IC1的稳压特性决定，并将输出电压稳定在IC1的输出限压值范围内。
第二实施例
本实施例与第一实施例的区别在于：
电压限制电路是一个稳压电路，包括第二电阻R2，第三电阻R3，第一NPN三极管Q1、第一电容C2和第二稳压二极管Z2。
所述的第二电阻R2连接于输入电压Vin和第一NPN三极管Q1的C极之间，所述的第三电阻R3连接于输入电压Vin和第一NPN三极管Q1的B极之间；所述的第一NPN三极管Q1的B极连接所述的第二稳压二极管Z2的阴极，E极连接驱动电路的输出端VDD；所述的第二稳压二极管Z2的阳极连接地GND；所述的第一电容C1连接于驱动电路的输出端VDD与地GND之间。
第一稳压二极管Z1的稳压值需小于第二稳压二极管Z2的稳压值，如第一稳压二极管Z1选择5.1V的稳压二极管，第二稳压二极管Z2选择12V的稳压二极管
下面结合图5对本发明的工作过程说明如下：
工作状态1供电装置正常工作，输入电压小于驱动电路判断电压区间的最小值时，启动电路输出电压与输入电压几乎无压差：
当输入电压未达到稳压二极管Z1的稳压值时，稳压二极管Z1于截止状态，输入电压Vin通过电阻R1对N-MOS管TR1的G、S电容和电容C1充电，使得N-MOS管TR1的G极对GND的电压等于输入电压Vin，N-MOS管TR1的G极电压大于S极电压，N-MOS管TR1导通，使得启动电路的输出电压与输入电压几乎无压差。
工作状态2供电装置正常工作，输入电压在驱动电路判断电压区间内时，启动电路输出电压与输入电压的压差随输入电压的增大缓慢增大：
当输入电压逐渐升高到大于稳压二极管Z1的稳压值，且小于时稳压二极管Z1的稳压值与N-MOS管TR1的门限电压值VT的绝对值相加的电压值时，驱动电路的输出信号Vg电压值稳定在稳压二极管Z1的稳压值，N-MOS管进入放大区，Vin与VDD之间电流由N-MOS管与由R2、R3、Q1和Z2组成的线性稳压电路共同提供，Vin缓慢上升的过程中，启动电路输出电压VDD与Vin之间的压差跟随N-MOS管进入放大区而缓慢增大。
工作状态3供电装置正常工作，输入电压超过驱动电路判断电压区间的最大值时，启动电路输出电压稳定在一个电压值或稳定在一个输出电压范围，与 输入电压的变化无关：
当输入电压Vin超过驱动电路判断电压区间的最大值时，即输入电压Vin大于稳压二极管Z1的稳压值与N-MOS管TR1的门限电压值VT相加的电压值时，N-MOS管进入截止区，Vin与VDD之间电流只由R2、R3、Q1和Z2组成的线性稳压电路提供，启动电路输出电压VDD直接由R2、R3、Q1和Z2组成的线性稳压电路的稳压特性决定，并将输出电压稳定在稳压二极管Z1的稳压值减去三级管Q1的B、E的体二极管压降。
以上仅是本发明的优选实施方式，应当指出的是，上述优选实施方式不应视为本发明的限制，在本发明图3原理框图的基础上，对于本技术领域的普通技术人员来说，在不脱离本发明的精神和范围内，还可以做出另外的改进及润饰，这些改进及润饰也在本发明的保护范围，这里不再用实施例赘述，本发明的保护范围应当以权利要求所限定的范围为准。

Claims (7)

  1. 一种低导通压降的启动电路，其特征在于：包括N-MOS管、驱动电路和电压限制电路；
    所述的驱动电路的输入端连接输入电压Vin，对输入电压Vin进行电压采样后产生控制电压Vg，所述控制电压Vg输出给N-MOS管的栅极，N-MOS管的漏极连接输入电压Vin，N-MOS管的源极连接到启动电路的输出端，为后级电路供电；电压限制电路的输入端和输出端分别连接在N-MOS管的漏极和源极；
    所述的驱动电路设有判断电压区间，当所述的输入电压Vin小于驱动电路判断电压区间的最小值时，所述的N-MOS管导通，将所述的电压限制电路短路，由N-MOS管的源极为后级电路供电；
    当所述的输入电压Vin在驱动电路判断电压区间内时，所述的N-MOS管和所述的电压限制电路都导通，由N-MOS管的源极和电压限制电路的输出端共同为后级电路供电；
    当所述的输入电压Vin大于驱动电路判断电压区间的最大值时，所述的N-MOS管关断，由所述的电压限制电路的输出端为后级电路供电。
  2. 根据权利要求1所述的一种低导通压降的启动电路，其特征在于：所述的电压限制电路是将输入电压Vin转换为稳定的输出电压范围的电压钳位电路，或者是将输入电压Vin转换为固定的输出电压值的稳压电路。
  3. 根据权利要求2所述的一种超宽输入电压的启动电路，其特征在于：所述的电压钳位电路包括第一芯片，所述第一芯片的输入端连接输入电压Vin，所述第一芯片的接地端接地，所述第一芯片的输出端连接N-MOS管的源极。
  4. 根据权利要求2所述的一种低导通压降的启动电路，其特征在于：所述的稳压电路包括第二电阻、第三电阻、第一NPN三极管、第一电容和第二稳压二极管；所述的第二电阻连接于输入电压Vin和第一NPN三极管的集电极之间，所述的第三电阻连接于输入电压Vin和第一NPN三极管的基极之间；所述的第一NPN三极管的基极连接所述的第二稳压二极管的阴极，第一NPN三极管的发射极连接驱动电路的输出端VDD；所述的第二稳压二极管的阳极连接地；所述的第一电容连接于驱动电路的输出端VDD与地之间。
  5. 根据权利要求4所述的一种超宽输入电压的启动电路，其特征在于：所述的驱动电路包括第一电阻和第一稳压二极管，所述的第一电阻的一端连接于输入电压Vin，第一电阻的另一端与所述的第一稳压二极管的阴极相连，并且连接点作为驱动电路的输出端输出控制电压Vg，第一稳压二极管的阳极与接地。
  6. 根据权利要求5所述的一种低导通压降的启动电路，其特征在于：所述第一稳压二极管的稳压值小于第二稳压二极管的稳压值。
  7. 根据权利要求6所述的一种低导通压降的启动电路，其特征在于：所述的驱动电路判断电压区间的最小值为第一稳压二极管的稳压值，所述的驱动电路判断电压区间的最大值为第一稳压二极管的稳压值与N-MOS管的门限电压值之和。
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Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108173425A (zh) * 2018-02-26 2018-06-15 广州金升阳科技有限公司 一种启动电路
CN108173426A (zh) * 2018-02-26 2018-06-15 广州金升阳科技有限公司 一种低导通压降的启动电路
CN108233693A (zh) * 2018-02-26 2018-06-29 广州金升阳科技有限公司 一种超低输入电压的启动电路
CN111060793B (zh) * 2019-11-13 2021-09-28 南京航空航天大学 直流固态功率控制器的功率管导通电压的在线测量电路
CN113131740A (zh) * 2019-12-31 2021-07-16 华润微集成电路(无锡)有限公司 控制电压切换电路及相应的升压电路
TWI713287B (zh) 2020-03-19 2020-12-11 捷拓科技股份有限公司 寬輸入電壓範圍的輔助電源供應電路
CN113433996B (zh) * 2020-03-23 2023-05-23 捷拓科技股份有限公司 宽输入电压范围的辅助电源供应电路

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09238466A (ja) * 1996-02-29 1997-09-09 Toshiba Lighting & Technol Corp 電源装置、放電灯点灯装置及び照明装置
CN202818087U (zh) * 2012-07-30 2013-03-20 中国航天科工集团第三研究院第八三五七研究所 高压输入开关电源启动电路
CN103414331A (zh) * 2013-08-22 2013-11-27 矽力杰半导体技术(杭州)有限公司 一种软启动电路
CN106452040A (zh) * 2016-10-20 2017-02-22 广州金升阳科技有限公司 启动电路
CN108173426A (zh) * 2018-02-26 2018-06-15 广州金升阳科技有限公司 一种低导通压降的启动电路
CN108173425A (zh) * 2018-02-26 2018-06-15 广州金升阳科技有限公司 一种启动电路
CN108233693A (zh) * 2018-02-26 2018-06-29 广州金升阳科技有限公司 一种超低输入电压的启动电路
CN207819757U (zh) * 2018-02-26 2018-09-04 广州金升阳科技有限公司 一种启动电路
CN207926436U (zh) * 2018-02-26 2018-09-28 广州金升阳科技有限公司 一种超低输入电压的启动电路
CN208046449U (zh) * 2018-02-26 2018-11-02 广州金升阳科技有限公司 一种低导通压降的启动电路

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103532584A (zh) * 2012-07-03 2014-01-22 成都市宏山科技有限公司 用于调频对讲机的稳压电路
CN107241018A (zh) * 2017-08-08 2017-10-10 深圳市三旺通信技术有限公司 一种宽电压输入转低电压大功率输出电路及方法

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09238466A (ja) * 1996-02-29 1997-09-09 Toshiba Lighting & Technol Corp 電源装置、放電灯点灯装置及び照明装置
CN202818087U (zh) * 2012-07-30 2013-03-20 中国航天科工集团第三研究院第八三五七研究所 高压输入开关电源启动电路
CN103414331A (zh) * 2013-08-22 2013-11-27 矽力杰半导体技术(杭州)有限公司 一种软启动电路
CN106452040A (zh) * 2016-10-20 2017-02-22 广州金升阳科技有限公司 启动电路
CN108173426A (zh) * 2018-02-26 2018-06-15 广州金升阳科技有限公司 一种低导通压降的启动电路
CN108173425A (zh) * 2018-02-26 2018-06-15 广州金升阳科技有限公司 一种启动电路
CN108233693A (zh) * 2018-02-26 2018-06-29 广州金升阳科技有限公司 一种超低输入电压的启动电路
CN207819757U (zh) * 2018-02-26 2018-09-04 广州金升阳科技有限公司 一种启动电路
CN207926436U (zh) * 2018-02-26 2018-09-28 广州金升阳科技有限公司 一种超低输入电压的启动电路
CN208046449U (zh) * 2018-02-26 2018-11-02 广州金升阳科技有限公司 一种低导通压降的启动电路

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