CN113691115B - Dual-drive power supply slow start circuit - Google Patents

Dual-drive power supply slow start circuit Download PDF

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Publication number
CN113691115B
CN113691115B CN202110976529.7A CN202110976529A CN113691115B CN 113691115 B CN113691115 B CN 113691115B CN 202110976529 A CN202110976529 A CN 202110976529A CN 113691115 B CN113691115 B CN 113691115B
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resistor
power supply
circuit
switch tube
power switch
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CN113691115A (en
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闵田
聂辉
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Fiberhome Telecommunication Technologies Co Ltd
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Fiberhome Telecommunication Technologies Co Ltd
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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
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/02—Details
    • H02H3/05—Details with means for increasing reliability, e.g. redundancy arrangements
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/24—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to undervoltage or no-voltage
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
    • H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
    • H02H7/1203—Circuits independent of the type of conversion
    • 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
    • H02M1/00—Details of apparatus for conversion
    • H02M1/32—Means for protecting converters other than automatic disconnection

Abstract

The application relates to a dual-drive power supply slow start circuit which comprises a power switch tube, a first-stage drive circuit and a second-stage drive circuit, wherein the source electrode of the power switch tube is connected with an input power supply, and the drain electrode of the power switch tube is connected with an output power supply; the input end of the first-stage driving circuit is connected with an input power supply, and the output end of the first-stage driving circuit is connected between the source electrode and the grid electrode of the power switch tube; the input end of the second-stage driving circuit is connected with an output power supply, the output end of the second-stage driving circuit is connected between the drain electrode and the grid electrode of the power switch tube and is used for starting working after the power switch tube is driven to be conducted, driving self-locking is achieved, and the output power supply is guaranteed to normally output; meanwhile, when the input power source drops to an undervoltage working point, the first-stage driving circuit and the second-stage driving circuit simultaneously control the power switch tube to be disconnected. The dual-drive power supply slow start circuit provided by the application can realize self-excitation drive power supply, an under-voltage protection function and better drive reliability; the input power supply can be prevented from being triggered to output by mistake when oscillation occurs, and the safety performance is better.

Description

Dual-drive power supply slow start circuit
Technical Field
The application relates to the technical field of power supply application, in particular to a dual-drive power supply slow start circuit.
Background
With the continuous development of communication technology, the communication equipment has higher and higher requirements on power supply, so that the power protection technology is wider in power supply application, and a power supply slow start circuit is generally used for protecting the power supply.
The existing power supply slow start circuit adopts a single drive control mode, and an auxiliary drive power supply and a drive chip are additionally needed to realize a slow start function. However, in the existing single drive control mode, the PMOS power switch is vulnerable when the power-on input power oscillates, and the circuit fails when the drive circuit fails.
Based on this, how to solve the situation that the related art is easy to trigger by mistake and power failure occurs, and it is our research and development core to improve the reliability of the power supply slow start circuit.
Disclosure of Invention
The embodiment of the application provides a dual-drive power supply slow start circuit, which is used for solving the problems that the prior art is easy to trigger by mistake and power failure occurs and improving the reliability of the power supply slow start circuit.
In a first aspect, a dual drive power supply slow start circuit is provided, comprising:
the source electrode of the power switch tube T3 is connected with the input power supply, and the drain electrode of the power switch tube T3 is connected with the output power supply;
the input end of the first-stage driving circuit is connected with an input power supply, the output end of the first-stage driving circuit is connected between the source electrode and the grid electrode of the power switch tube T3 and is used for controlling the power switch tube T3 to be turned on or turned off and controlling the power switch tube T3 to be turned off when the input power supply oscillates so as to prevent the power switch tube T3 from being turned on by mistake;
the input end of the second-stage driving circuit is connected with an output power supply, the output end of the second-stage driving circuit is connected between the drain electrode and the grid electrode of the power switch tube T3 and is used for starting to work after the power switch tube T3 is driven and conducted, driving self-locking is achieved, and the output power supply is guaranteed to normally output; at the same time, the method comprises the steps of,
when the input power source drops to an under-voltage working point, the first-stage driving circuit and the second-stage driving circuit simultaneously control the power switch tube T3 to be disconnected, so that under-voltage protection is realized.
In some embodiments, the first stage drive circuit includes:
the first driving charge discharging circuit comprises a resistor R1, a resistor R2 and a capacitor C1, wherein the resistor R1 and the capacitor C1 are connected in parallel and then connected with the resistor R2 in series, one end of the resistor R1, which is far away from the resistor R2, is connected with an input power supply, and one end of the resistor R2, which is far away from the resistor R1, is grounded;
a first voltage dividing circuit including a resistor R3 and a resistor R4, the resistor R3 and the resistor R4 being connected in series between an input power source and ground;
a diode D1 having an anode connected to a connection point between the resistor R3 and the resistor R4 and a cathode connected to a connection point between the resistor R1 and the resistor R2;
the first driving circuit comprises a first transistor T1, a resistor R5, a capacitor C2 and a voltage stabilizing tube ZD1, wherein the drain electrode of the first transistor T1 is connected with the source electrode and the grid electrode of the power switch tube T3, the grid electrode of the first transistor T1 is grounded after passing through the resistor R5 and the capacitor C2 in sequence, the source electrode of the first transistor T1 is grounded, the anode of the voltage stabilizing tube ZD1 is connected between the resistor R5 and the capacitor C2, and the cathode of the voltage stabilizing tube ZD1 is connected between the resistor R3 and the resistor R4.
In some embodiments, the second stage drive circuit includes:
a second voltage dividing circuit including a resistor R9 and a resistor R10, the resistor R9 and the resistor R10 being connected in series between an output power supply and ground;
the second driving circuit comprises a second transistor T2, a resistor R8, a capacitor C5 and a voltage stabilizing tube ZD2, wherein the drain electrode of the second transistor T2 is connected with the source electrode and the grid electrode of the power switch tube T3, the grid electrode of the second transistor T2 is grounded after passing through the resistor R8 and the capacitor C5 in sequence, the source electrode of the second transistor T2 is grounded, the anode of the voltage stabilizing tube ZD2 is connected between the resistor R8 and the capacitor C5, and the cathode of the voltage stabilizing tube ZD2 is connected between the resistor R9 and the resistor R10.
In some embodiments, the second voltage dividing circuit further includes a diode D2, where the diode D2 is connected in series between the resistor R9 and the resistor R10, and an anode of the diode D2 is connected to the resistor R9, and a cathode of the diode D2 is connected to a junction between the voltage regulator ZD2 and the resistor R10.
In some embodiments, the dual-drive power supply slow start circuit further includes a current limiting circuit, the current limiting circuit includes a resistor R6 and a resistor R7, the resistor R6 and the resistor R7 are connected in series with the source and the gate of the power switch tube T3, and the output end of the first stage driving circuit and the output end of the second stage driving circuit are both connected between the resistor R6 and the resistor R7.
In some embodiments, the dual-drive power supply slow start circuit further includes a capacitor C4, one end of which is connected between the resistor R6 and the resistor R7, and the other end of which is grounded.
In some embodiments, the dual-drive power supply slow start circuit further includes a transient suppression diode TD1, an anode of which is grounded, and a cathode of which is connected to the input power supply.
In some embodiments, the dual-drive power supply slow start circuit further comprises a diode D3 and a capacitor C6 connected in parallel, wherein an anode of the diode D3 is grounded, and a cathode of the diode D is connected with the output power supply.
In some embodiments, the dual-drive power supply slow start circuit further includes a fuse FU1, where the fuse FU1 is connected between the source of the power switch tube T3 and the input power supply.
In some embodiments, the power switch transistor T3 is a PMOS transistor, and the first transistor T1 and the second transistor T2 are NMOS transistors.
The beneficial effects that technical scheme that this application provided brought include: the self-excitation driving power supply can be realized, the undervoltage protection function is realized, and the reliability is better; the false triggering and conduction can be prevented, and the safety performance is better.
The embodiment of the application provides a dual-drive power supply slow start circuit, because a power switch tube T3 is jointly driven by a first-stage drive circuit and a second-stage drive circuit, the input power supply VIN is connected to the first-stage drive circuit, the output power supply VO is connected to the second-stage drive circuit, and when the output power supply VO is normally output, on one hand, the driving self-locking can be realized, and even if the input power supply generates micro-oscillation to cause the first transistor T1 to be cut off, the power switch tube T3 can be controlled to be conducted through the second transistor T2, so that the slow start circuit cannot be powered down due to the micro-oscillation of the input power supply, and the normal power supply of the power supply is ensured; on the other hand, only after the input power source VIN drops to the undervoltage operating point of the voltage stabilizing tube, the first transistor T1 and the second transistor T2 are all cut off, and then the power switch tube T3 is controlled to be disconnected, so that the undervoltage protection function is realized, and therefore, the driving reliability of the dual-driving power source slow starting circuit is better, an additional auxiliary power source and a driving chip are not needed, the circuit structure is simpler, the cost is lower, false triggering output when the input power source oscillates can be prevented, and the safety is better.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic diagram of a dual-drive power supply slow start circuit provided in an embodiment of the present application;
fig. 2 is a schematic diagram of another dual-drive power source slow start circuit according to an embodiment of the present application.
Detailed Description
For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present application based on the embodiments herein.
Referring to fig. 1, an embodiment of the present application provides a dual-drive power source slow start circuit, which includes a power switch tube T3, a first stage driving circuit and a second stage driving circuit.
The source electrode of the power switch tube T3 is connected with an input power supply, and the drain electrode of the power switch tube T3 is connected with an output power supply;
the input end of the first-stage driving circuit is connected with an input power supply, the output end of the first-stage driving circuit is connected between the source electrode and the grid electrode of the power switch tube T3, and the first-stage driving circuit is used for controlling the power switch tube T3 to be turned on or off and controlling the power switch tube T3 to be turned off when the input power supply oscillates so as to prevent the power switch tube T3 from being turned on by mistake;
the input end of the second-stage driving circuit is connected with an output power supply, the output end of the second-stage driving circuit is connected between the drain electrode and the grid electrode of the power switch tube T3, and the second-stage driving circuit is used for starting to work after the power switch tube T3 is driven and conducted, so that driving self-locking is realized, and the normal output of the output power supply is ensured; at the same time, the method comprises the steps of,
when the input power source drops to an under-voltage working point, the first-stage driving circuit and the second-stage driving circuit simultaneously control the power switch tube T3 to be disconnected, so that under-voltage protection is realized.
In the embodiment of the application, the input power supply is denoted as VIN, the output power supply is denoted as VO, the power switch tube T3 is jointly driven by the first-stage driving circuit and the second-stage driving circuit, the input power supply VIN is connected to the first-stage driving circuit, the output power supply VO is connected to the second-stage driving circuit, and after the output power supply VO is normally output, on one hand, the driving self-locking can be realized, and even if the first transistor T1 is turned off due to the small oscillation of the input power supply, the power switch tube T3 can be still controlled to be turned on through the second transistor T2, so that the slow starting circuit can not be powered down due to the small oscillation of the input power supply, and the normal power supply of the power supply is ensured; on the other hand, only after the input power supply VIN drops to the undervoltage working point of the voltage stabilizing tube, the first transistor T1 and the second transistor T2 are both cut off, so that the power switch tube T3 is controlled to be disconnected, and the undervoltage protection function is realized. Compared with the prior art, the dual-drive power supply slow start circuit disclosed by the embodiment of the application has the advantages that the two drive circuits jointly control the power switch tube T3 to be turned on or turned off, when the power supply is stably output, self-excited drive power supply can be realized, when the input power supply falls to an under-voltage working point, the power switch tube T3 is controlled to be turned off, an under-voltage protection function is realized, and the driving reliability is better; and when the input power supply is electrified and vibration occurs, the power switch tube T3 is prevented from being triggered and conducted by mistake, and the safety performance is better.
Still further, in an embodiment of the present application, the first stage driving circuit includes a first driving charge discharging circuit, a first voltage dividing circuit, a diode D1, and a first driving circuit.
The first driving charge discharging circuit comprises a resistor R1, a resistor R2 and a capacitor C1, wherein the resistor R1 and the capacitor C1 are connected in parallel and then connected with the resistor R2 in series, one end, far away from the resistor R2, of the resistor R1 is connected with an input power supply, and one end, far away from the resistor R1, of the resistor R2 is grounded.
The first voltage dividing circuit comprises a resistor R3 and a resistor R4, and the resistor R3 and the resistor R4 are connected in series between an input power supply and ground.
The diode D1 has an anode connected to the connection point of the resistor R3 and the resistor R4, and a cathode connected to the connection point of the resistor R1 and the resistor R2.
The first driving circuit comprises a first transistor T1, a resistor R5, a capacitor C2 and a voltage stabilizing tube ZD1, wherein the drain electrode of the first transistor T1 is connected with the source electrode and the grid electrode of the power switch tube T3, the grid electrode of the first transistor T1 is grounded after passing through the resistor R5 and the capacitor C2 in sequence, the source electrode of the first transistor T1 is grounded, the anode of the voltage stabilizing tube ZD1 is connected between the resistor R5 and the capacitor C2, and the cathode of the voltage stabilizing tube ZD1 is connected between the resistor R3 and the resistor R4.
Still further, in an embodiment of the present application, the second stage driving circuit includes a second voltage dividing circuit and a second driving circuit.
The second voltage dividing circuit comprises a resistor R9 and a resistor R10, and the resistor R9 and the resistor R10 are connected in series between the output power supply and the ground.
The second driving circuit comprises a second transistor T2, a resistor R8, a capacitor C5 and a voltage stabilizing tube ZD2, wherein the drain electrode of the second transistor T2 is connected with the source electrode and the grid electrode of the power switch tube T3, the grid electrode of the second transistor T2 is grounded after passing through the resistor R8 and the capacitor C5 in sequence, the source electrode of the second transistor T2 is grounded, the anode of the voltage stabilizing tube ZD2 is connected between the resistor R8 and the capacitor C5, and the cathode of the voltage stabilizing tube ZD2 is connected between the resistor R9 and the resistor R10.
Still further, in this embodiment of the present application, the second voltage dividing circuit further includes a diode D2, where the diode D2 is connected in series between the resistor R9 and the resistor R10, and an anode of the diode D2 is connected to the resistor R9, and a cathode of the diode D2 is connected to a junction between the voltage stabilizing tube ZD2 and the resistor R10.
Still further, in this embodiment of the present application, the dual-drive power supply slow start circuit further includes a current limiting circuit, where the current limiting circuit includes a resistor R6 and a resistor R7, the resistor R6 and the resistor R7 are connected in series with the source and the gate of the power switch tube T3, and the output end of the first stage driving circuit and the output end of the second stage driving circuit are both connected between the resistor R6 and the resistor R7.
Still further, in the embodiment of the present application, the dual-driving power slow start circuit further includes a capacitor C3, and the capacitor C3 is connected across the source and the gate of the power switch tube T3.
As shown in fig. 2, in this embodiment, the dual-drive power supply slow start circuit further includes a capacitor C4, where one end of the capacitor C4 is connected between the resistor R6 and the resistor R7, and the other end is grounded.
Further, in the embodiment of the present application, the dual-driving power slow-start circuit further includes a transient suppression diode TD1, where an anode is grounded and a cathode is connected to the input power.
The transient suppression diode TD1, also called TVS, is a diode-type high-efficiency protection device, and utilizes the reverse breakdown working principle of the P-N junction to introduce the high-voltage pulse of static electricity to the ground, so that the components in the dual-drive power supply slow-start circuit can be protected.
Furthermore, in the embodiment of the present application, the dual-driving power source slow-start circuit further includes a diode D3 and a capacitor C6 connected in parallel, where an anode of the diode D3 is grounded, and a cathode of the diode D is connected to the output power source.
Still further, in this embodiment of the present application, the dual-drive power supply soft start circuit further includes a fuse FU1, where the fuse FU1 is connected between the source of the power switch tube T3 and the input power supply, so that the dual-drive power supply soft start circuit may be protected.
Preferably, in the embodiment of the present application, the power switch transistor T3 is a PMOS transistor, and the first transistor T1 and the second transistor T2 are NMOS transistors.
The dual-drive power supply slow start circuit comprises a plurality of transistors, resistors, capacitors, voltage stabilizing tubes and the like, and adopts discrete devices to build the circuit, so that a drive control chip and an auxiliary power supply are reduced, the cost is reduced, the dual-drive power supply slow start circuit is simple in structure, the parameter configuration flexibility is better, and the practicality is better.
Preferably, in the embodiment of the present application, the ratio of the resistor R1 to the resistor R2, and the ratio of the resistor R3 to the resistor R4 are approximately equal, where the resistor R1 and the resistor R2 are kΩ, and the resistor R3 and the resistor R4 are mΩ.
In the embodiment of the present application, since the delay turn-on time of the first transistor T1 is related to the resistor R3 and the capacitor C2, the delay turn-on time of the first transistor T1 may be adjusted by setting the parameter configuration of the resistor R3 and the capacitor C2, and the delay turn-on time of the second transistor T2 is related to the resistor R9 and the capacitor C5, and the delay turn-on time of the second transistor T2 may be adjusted by setting the parameter configuration of the resistor R9 and the capacitor C5; and furthermore, the conduction delay time of the power switch tube T3 can be adjusted, the slow start output of the circuit is realized, and the power switch tube T3 is ensured not to be damaged due to overlarge transient conduction power.
In this embodiment of the present application, the input power supply is denoted VIN, the output power supply is denoted VO, the voltage at the junction of the resistor R1 and the resistor R2 is denoted V1, the voltage at the junction of the resistor R3 and the resistor R4 is denoted V2, the voltage at the junction of the regulator tube ZD1 and the resistor R5 is denoted VT1, the drain voltage of the first transistor T1 is denoted V3, the voltage at the junction of the resistor R9 and the resistor R10 is denoted V4, and the voltage at the junction of the regulator tube ZD2 and the resistor R8 is denoted VT2.
The working principle of the dual-drive power supply slow start circuit is as follows:
when VIN is just connected into a power supply, VIN voltage starts to climb from 0V, when V2 is smaller than the undervoltage threshold of the voltage stabilizing tube ZD1, the voltage stabilizing tube ZD1 is cut off, the voltage stabilizing tube is cut off by v1=0V, the first transistor T1 is cut off, the VGS=0 of the first transistor T3, the power switch tube T3 is cut off, the output power supply VO=0, and no output of the circuit is ensured;
when V2 is larger than the undervoltage threshold of the voltage stabilizing tube ZD1 and VIN is in oscillation, particularly falling, V1 is smaller than V2, the diode D1 is conducted, the voltage of the capacitor C2 and the grid charge of the first transistor T1 are rapidly released through the voltage stabilizing tube ZD1, the diode D1, the capacitor C1 and the resistor R2, so that the voltage of VT1 is lower than the starting threshold voltage of the first transistor T1, the first transistor T1 is cut off, the voltage VGS of the grid electrode and the source electrode of the power switching tube T3 is=0, the power switching tube T3 is cut off, the output power source VO=0, and no output of the circuit is ensured when the circuit is in oscillation when the circuit is input;
when V2 is greater than the undervoltage threshold of the voltage stabilizing tube ZD1 and the input is stable, v1=v2, the diode D1 is turned off, the capacitor C2 is charged, when VT1 is higher than the on threshold of the first transistor T1, the first transistor T1 is turned on, the drain voltage v3=0v of the first transistor T1, the voltage vgs= -VIN of the gate and source of the power switching tube T3, the power switching tube T3 is turned on, the output power vo=vin, and the circuit has a steady output;
after the power switch tube T3 is conducted, the output power supply VO=VIN, through the parameter configuration of the resistor R9, the resistor R10, the capacitor C5 and the voltage stabilizing tube ZD2, the V4 is larger than the undervoltage threshold of the voltage stabilizing tube ZD2, the voltage stabilizing tube ZD2 is conducted, the capacitor C5 is charged, when the VT2 is higher than the opening threshold of the second transistor T2, the second transistor T2 is conducted, and the output power supply VO is conducted in cooperation with the conduction of T1, so that the normal output of the output power supply VO is doubly ensured;
after VO outputs normally, when VIN voltage oscillates, the first transistor T1 will be turned off, but at this time, VT2 will not discharge due to the effect of the diode D2, the second transistor T2 is still in a conducting state, and only when VIN drops below the undervoltage threshold of the voltage stabilizing tube ZD1, the output power VO will drop below the undervoltage threshold of the voltage stabilizing tube ZD2, and because the second transistor T2 is connected with the output power VO, the second transistor T2 will be turned off, so that the power switch tube T3 is turned off, and the output power VO is not output.
Therefore, the embodiment of the application adopts the dual-drive power supply slow start circuit, the two-stage drive circuit sequentially and slowly starts final dual-drive to simultaneously act to realize circuit output self-locking, the power supply is ensured to normally output and work in a dual mode, when the input voltage is greatly oscillated and voltage drops during starting, the first-stage drive circuit can be locked to prevent the PMOS power tube from being turned on by mistake and the novel technology of over-power damage is realized, and the protection function of the starting power PMOS tube is realized. Compared with the existing single-drive control mode, the circuit driving reliability is higher in the embodiment of the application.
In the description of the present application, it should be noted that the azimuth or positional relationship indicated by the terms "upper", "lower", etc. are based on the azimuth or positional relationship shown in the drawings, and are merely for convenience of description of the present application and simplification of the description, and are not indicative or implying that the apparatus or element in question must have a specific azimuth, be configured and operated in a specific azimuth, and thus should not be construed as limiting the present application. Unless specifically stated or limited otherwise, the terms "mounted," "connected," and "coupled" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.
It should be noted that in this application, relational terms such as "first" and "second" and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The foregoing is merely a specific embodiment of the application to enable one skilled in the art to understand or practice the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (12)

1. A dual drive power supply slow start circuit, comprising:
the source electrode of the power switch tube T3 is connected with the input power supply, and the drain electrode of the power switch tube T3 is connected with the output power supply;
the input end of the first-stage driving circuit is connected with an input power supply, the output end of the first-stage driving circuit is connected between the source electrode and the grid electrode of the power switch tube T3 and is used for controlling the power switch tube T3 to be turned on or turned off and controlling the power switch tube T3 to be turned off when the input power supply oscillates so as to prevent the power switch tube T3 from being turned on by mistake;
the input end of the second-stage driving circuit is connected with an output power supply, the output end of the second-stage driving circuit is connected between the drain electrode and the grid electrode of the power switch tube T3 and is used for starting to work after the power switch tube T3 is driven and conducted, driving self-locking is achieved, and the output power supply is guaranteed to normally output; at the same time, the method comprises the steps of,
when the input power source drops to an under-voltage working point, the first-stage driving circuit and the second-stage driving circuit simultaneously control the power switch tube T3 to be disconnected, so that under-voltage protection is realized.
2. The dual drive power supply slow start circuit of claim 1, wherein the first stage drive circuit comprises:
the first driving charge discharging circuit comprises a resistor R1, a resistor R2 and a capacitor C1, wherein the resistor R1 and the capacitor C1 are connected in parallel and then connected with the resistor R2 in series, one end of the resistor R1, which is far away from the resistor R2, is connected with an input power supply, and one end of the resistor R2, which is far away from the resistor R1, is grounded;
a first voltage dividing circuit including a resistor R3 and a resistor R4, the resistor R3 and the resistor R4 being connected in series between an input power source and ground;
a diode D1 having an anode connected to a connection point between the resistor R3 and the resistor R4 and a cathode connected to a connection point between the resistor R1 and the resistor R2;
the first driving circuit comprises a first transistor T1, a resistor R5, a capacitor C2 and a voltage stabilizing tube ZD1, wherein the drain electrode of the first transistor T1 is connected with the source electrode and the grid electrode of the power switch tube T3, the grid electrode of the first transistor T1 is grounded after passing through the resistor R5 and the capacitor C2 in sequence, the source electrode of the first transistor T1 is grounded, the anode of the voltage stabilizing tube ZD1 is connected between the resistor R5 and the capacitor C2, and the cathode of the voltage stabilizing tube ZD1 is connected between the resistor R3 and the resistor R4.
3. The dual drive power supply slow start circuit of claim 1, wherein the second stage drive circuit comprises:
a second voltage dividing circuit including a resistor R9 and a resistor R10, the resistor R9 and the resistor R10 being connected in series between an output power supply and ground;
the second driving circuit comprises a second transistor T2, a resistor R8, a capacitor C5 and a voltage stabilizing tube ZD2, wherein the drain electrode of the second transistor T2 is connected with the source electrode and the grid electrode of the power switch tube T3, the grid electrode of the second transistor T2 is grounded after passing through the resistor R8 and the capacitor C5 in sequence, the source electrode of the second transistor T2 is grounded, the anode of the voltage stabilizing tube ZD2 is connected between the resistor R8 and the capacitor C5, and the cathode of the voltage stabilizing tube ZD2 is connected between the resistor R9 and the resistor R10.
4. A dual drive power supply slow start circuit according to claim 3, wherein the second voltage dividing circuit further comprises a diode D2, the diode D2 is connected in series between a resistor R9 and a resistor R10, an anode of the diode D2 is connected with the resistor R9, and a cathode of the diode D2 is connected at a junction of the voltage stabilizing tube ZD2 and the resistor R10.
5. The dual drive power supply slow start circuit as set forth in claim 1 further comprising a current limiting circuit, wherein the current limiting circuit comprises a resistor R6 and a resistor R7, the resistor R6 and the resistor R7 are connected in series with the source and the gate of the power switch tube T3, and the output end of the first stage drive circuit and the output end of the second stage drive circuit are connected between the resistor R6 and the resistor R7.
6. The dual drive power supply slow start circuit as set forth in claim 5 further comprising a capacitor C4 having one end connected between said resistor R6 and resistor R7 and the other end grounded.
7. The dual drive power supply slow start circuit according to claim 1, further comprising a transient suppression diode TD1 having an anode connected to ground and a cathode connected to the input power supply.
8. The dual drive power supply slow start circuit according to claim 1, further comprising a diode D3 and a capacitor C6 connected in parallel, wherein an anode of the diode D3 is grounded, and a cathode is connected to an output power supply.
9. The dual drive power supply soft start circuit of claim 1, further comprising a fuse FU1, the fuse FU1 being connected between the source of the power switch tube T3 and an input power supply.
10. The dual drive power supply slow start circuit as set forth in claim 1, wherein said power switch tube T3 is a PMOS tube.
11. The dual drive power supply soft start circuit of claim 2, wherein the first transistor T1 is an NMOS transistor.
12. The dual drive power supply slow start circuit as set forth in claim 3, wherein said second transistor T2 is an NMOS transistor.
CN202110976529.7A 2021-08-24 2021-08-24 Dual-drive power supply slow start circuit Active CN113691115B (en)

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Publication number Priority date Publication date Assignee Title
US4748351A (en) * 1986-08-26 1988-05-31 American Telephone And Telegraph Company, At&T Bell Laboratories Power MOSFET gate driver circuit
CN101989852B (en) * 2009-07-30 2013-01-02 华为技术有限公司 Single board, communication equipment, device for controlling power on/off of single board and method thereof
US9548648B2 (en) * 2014-04-25 2017-01-17 Texas Instruments Incorporated Switched reference MOSFET drive assist circuit
CN205408217U (en) * 2016-02-18 2016-07-27 无锡市芯茂微电子有限公司 Led control chip and led constant current control circuit
CN109391253A (en) * 2017-08-11 2019-02-26 湖南金杯新能源发展有限公司 Both-end is double to drive control circuit
CN111146931B (en) * 2019-12-23 2021-12-14 广东美的白色家电技术创新中心有限公司 Drive circuit of power device and electronic equipment

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