CN111786545B

CN111786545B - Switching power supply driving circuit with protection function

Info

Publication number: CN111786545B
Application number: CN202010606631.3A
Authority: CN
Inventors: 梁英键
Original assignee: Foshan University
Current assignee: Huijiawang Tianjin Technology Co ltd; Guangdong Haiwu Technology Co Ltd
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2021-08-31
Anticipated expiration: 2040-06-29
Also published as: CN111786545A

Abstract

The invention discloses a switching power supply driving circuit with a protection function, which comprises a driving module, a half-bridge circuit, a load battery and a feedback control module, wherein the driving module is used for driving a switching power supply; the feedback control module comprises a dual-voltage comparator chip; thereby supply power for load battery through drive module drive switching power supply half-bridge circuit, adopt feedback control module to gather half-bridge circuit and load battery's voltage simultaneously and carry out the comparison, drive module is according to whether disconnection of comparative data control switching power supply to reach the effect of protection whole circuit, do benefit to switching power supply's steady operation, solved drive module complicacy, feedback control module components and parts are various and unstable problem.

Description

Switching power supply driving circuit with protection function

Technical Field

The invention relates to the technical field of switching power supply driving, in particular to a switching power supply driving circuit with a protection function.

Background

With the rapid development of power electronic technology, the power electronic equipment has increasingly close relationship with the work and life of people, and the power electronic equipment cannot be powered by a reliable power supply. In the development of nearly half a century or more, the switching power supply gradually replaces the continuous working power supply manufactured by the traditional technology due to the advantages of small volume, light weight, high efficiency, low heat productivity, stable performance and the like, and is widely applied to electronic complete machines and equipment.

The existing switching power supply using a half-bridge converter as a main component has the characteristics of large output power, high working efficiency, capability of bearing half of input voltage of each switching tube and the like, so that the application is very wide. However, the driving control is complex, and the feedback control is not favorable for reducing the cost and the stable operation of the switching power supply due to the adoption of various components.

Disclosure of Invention

The present invention is directed to a switching power supply driving circuit with protection function, so as to solve one or more technical problems in the prior art, and provide at least one of the advantages of the present invention.

The purpose of the invention is realized by adopting the following technical scheme: a switching power supply drive circuit with a protection function includes: the device comprises a driving module, a half-bridge circuit, a load battery and a feedback control module; the feedback control module includes a dual voltage comparator chip.

The half-bridge circuit is respectively connected with the driving module and the load battery, and the feedback control module is respectively connected with the driving module, the half-bridge circuit and the load battery; the driving module is used for driving the half-bridge circuit to supply power to the load battery; the feedback control module is used for acquiring the voltage of the half-bridge circuit and the voltage of the load battery, comparing the acquired voltage data and feeding back the data to the driving module.

Thereby supply power for load battery through drive module drive switching power supply half-bridge circuit, adopt feedback control module to gather half-bridge circuit and load battery's voltage simultaneously and carry out the comparison, drive module is according to whether disconnection of comparative data control switching power supply to reach the effect of protection whole circuit, do benefit to switching power supply's steady operation, solved drive module complicacy, feedback control module components and parts are various and unstable problem.

As a further improvement of the above technical solution, the driving module includes a four-way differential comparator chip, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a first triode, a second triode, a third triode, a fourth triode, a fifth triode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, and a fifth capacitor; a first pin of the four-way differential comparator chip is connected with the right end of the eighth resistor; a second pin of the four-way differential comparator chip is connected with the lower end of the fifth resistor, the right end of the fourth resistor and the right end of the first capacitor; a third pin of the four-way differential comparator chip is connected with the right end of the third capacitor, the collector of the first triode, the upper end of the first resistor, the upper end of the fifth resistor, the upper end of the seventh resistor, the upper end of the tenth resistor, the upper end of the twelfth resistor, the collector of the fourth triode and a power supply end; a fourth pin of the four-way differential comparator chip is respectively connected with the feedback control module, the right end of the second capacitor, the right end of the sixth resistor, the lower end of the seventh resistor and the left end of the eighth resistor; a fifth pin of the four-way differential comparator chip is respectively connected with a sixth pin of the four-way differential comparator chip, a ninth pin of the four-way differential comparator chip, a tenth pin of the four-way differential comparator chip, a lower end of the fourteenth resistor, an upper end of the fifteenth resistor and an upper end of the fifth capacitor; the seventh pin of the four-way differential comparator chip is respectively connected with the eighth pin of the four-way differential comparator chip and the PWM signal input end; an eleventh pin of the four-way differential comparator chip is respectively connected with the feedback control module, the left end of the fourth capacitor, the right end of the ninth resistor, the left end of the eleventh resistor and the lower end of the tenth resistor; the twelfth pin of the four-way differential comparator chip is connected with a ground terminal; a thirteenth pin of the four-way differential comparator chip is respectively connected with the lower end of the twelfth resistor and the left end of the thirteenth resistor; a fourteenth pin of the four-way differential comparator chip is connected with the left end of the ninth resistor respectively; the emitter of the first triode is respectively connected with the collector of the second triode and the half-bridge circuit; the base electrode of the first triode is respectively connected with the lower end of the first resistor, the left end of the second resistor and the base electrode of the second triode; the emitter of the second triode is connected with a grounding end; a collector of the third triode is connected with the right end of the second resistor, and an emitter of the third triode is respectively connected with the lower end of the third resistor and a ground terminal; the base electrode of the third triode is respectively connected with the left end of the first capacitor, the upper end of the third resistor and the left end of the fourth resistor; the left end of the sixth resistor is connected with the left end of the second resistor and the grounding end; the upper end of the fourteenth resistor is connected with a power supply end, and the lower end of the fifteenth resistor is connected with the lower end of the fifth capacitor and a ground end; the right end of the fourth capacitor is connected with the right end of the eleventh resistor and the ground end; the base electrode of the fourth triode is respectively connected with the right end of the thirteenth resistor and the base electrode of the fifth triode; an emitter of the fourth triode is respectively a collector of the fifth triode and the half-bridge circuit; and the emitter of the fifth triode is connected with the ground terminal.

As a further improvement of the above technical solution, the half-bridge circuit includes a first MOS transistor switch circuit and a second MOS transistor switch circuit, and the first MOS transistor switch circuit and the second MOS transistor switch circuit are alternately turned on. Avoiding the presence of semi-conducting regions.

As a further improvement of the above technical solution, the half-bridge circuit includes a sixth MOS transistor, a seventh MOS transistor, a first inductor, a twenty-seventh resistor, a twenty-eighth resistor, a twenty-ninth resistor, a thirty-eighth resistor, an eleventh capacitor, and a twelfth capacitor; a grid electrode of the sixth MOS transistor is connected to the driving module and the upper end of the twenty-seventh resistor respectively, a drain electrode of the sixth MOS transistor is connected to the upper end of the twelfth capacitor and the power supply end respectively, and a source electrode of the sixth MOS transistor is connected to the left end of the twenty-ninth resistor, the lower end of the twenty-seventh resistor, the drain electrode of the seventh MOS transistor and the power supply end respectively; a grid electrode of the seventh MOS tube is respectively connected with the driving module and the upper end of the twenty-eighth resistor, and a source electrode of the seventh MOS tube is respectively connected with the lower end of the twenty-eighth resistor, the upper end of the thirtieth resistor, the upper end of the thirty-first resistor and the lower end of the eleventh capacitor; the lower end of the twelfth capacitor is connected with the upper end of the eleventh capacitor and the lower end of the first inductor; the right end of the twenty-ninth resistor is connected with the upper end of the first inductor; the lower end of the thirty-third resistor is connected with the lower end of the thirty-first resistor and the ground terminal.

As a further improvement of the above technical solution, the feedback control module includes a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, a first diode, and a second diode; a first pin of the dual-voltage comparator chip is respectively connected with the upper end of the eighteenth resistor, the lower end of the twenty-sixth resistor, the cathode of the first diode, the cathode of the second diode, a seventh pin of the dual-voltage comparator chip and the upper end of the twenty-first resistor; a second pin of the dual-voltage comparator chip is respectively connected with the lower end of the nineteenth resistor, the upper end of the twentieth resistor, the upper end of the sixth capacitor and the upper end of the seventh capacitor; a third pin of the dual-voltage comparator chip is respectively connected with the right end of the sixteenth resistor, the lower end of the seventeenth resistor, the lower end of the eighteenth resistor and the upper end of the tenth capacitor; a fifth pin of the dual-voltage comparator chip is respectively connected with the lower end of the twenty-first resistor, the upper end of the twenty-second resistor and the left end of the twenty-third resistor; a sixth pin of the dual-voltage comparator chip is respectively connected with the upper end of the ninth capacitor, the upper end of the twenty-fourth resistor and the left end of the twenty-fifth resistor; an eighth pin of the dual-voltage comparator chip is respectively connected with the left end of the eighth capacitor and a power supply end; the upper end of the nineteenth resistor, the upper end of the seventeenth resistor, the right end of the twenty-third resistor and the upper end of the twenty-sixth resistor are respectively connected with power supply ends; the left end of the sixteenth resistor is connected with a load battery; the anode of the first diode and the anode of the second diode are respectively connected with the driving module; the right end of the twenty-fifth resistor is connected with the half-bridge circuit; the lower end of the twentieth resistor, the lower end of the sixth capacitor, the lower end of the tenth capacitor, the lower end of the seventh capacitor, the fourth pin of the dual-voltage comparator chip, the lower end of the twenty-second resistor, the right end of the eighth capacitor, the lower end of the ninth capacitor and the lower end of the twenty-fourth resistor are respectively connected with a ground terminal.

As a further improvement of the above technical solution, the model of the four-way differential comparator chip is LM 339.

As a further improvement of the above technical solution, the model of the dual voltage comparator chip is LM 393.

The invention has the beneficial effects that: the driving module drives the half-bridge circuit of the switching power supply to supply power to the load battery, the feedback control module is used for collecting and comparing the voltages of the half-bridge circuit and the load battery, and the driving module controls whether the switching power supply is disconnected according to comparison data, so that the effect of protecting the whole circuit is achieved, the stable work of the switching power supply is facilitated, and the problems that the driving module is complex, and components of the feedback control module are various and unstable are solved.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic structural diagram of a switching power supply driving circuit with a protection function according to the present invention;

fig. 2 is a circuit schematic diagram of a driving module and a feedback control module of a switching power supply driving circuit with a protection function provided by the invention;

fig. 3 is a half-bridge circuit diagram of a switching power supply driving circuit with a protection function according to the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and larger, smaller, larger, etc. are understood as excluding the number, and larger, smaller, inner, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.

Embodiment 1, referring to fig. 1 to 3, a switching power supply driving circuit with a protection function includes: the device comprises a driving module, a half-bridge circuit, a load battery and a feedback control module; the half-bridge circuit comprises a first MOS tube switching circuit and a second MOS tube switching circuit, and the first MOS tube switching circuit and the second MOS tube switching circuit are alternately switched on.

The half-bridge circuit is respectively connected with the driving module and the load battery, and the feedback control module is respectively connected with the driving module, the half-bridge circuit and the load battery; the driving module is used for driving the first MOS tube switching circuit and the second MOS tube switching circuit; the feedback control module is used for acquiring the voltage of the half-bridge circuit and the voltage of the load battery, comparing the acquired voltage data and feeding back the data to the driving module.

Referring to fig. 2, the driving module includes a four-way differential comparator chip U1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, a fifth transistor Q5, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4 and a fifth capacitor C5; a second pin Output1, a fourth pin Input1 and a fifth pin Input1+ of the four-way differential comparator chip U1 respectively correspond to an Output end, an inverting Input end and a non-inverting Input end of a first comparator in the four-way differential comparator chip U1; a first pin Output1, a sixth pin Input2 and a seventh pin Input2+ of the four-way differential comparator chip U1 respectively correspond to an Output end, an inverting Input end and a non-inverting Input end of a second comparator in the four-way differential comparator chip U1; the fourteenth pin Output3, the eighth pin Input3 and the ninth pin Input3+ of the four-way differential comparator chip U1 respectively correspond to an Output end, an inverting Input end and a non-inverting Input end of a third comparator inside the four-way differential comparator chip U1; the fourteenth pin Output4, the fourth pin Input4 and the fifth pin Input4+ of the four-way differential comparator chip U1 correspond to an Output end, an inverting Input end and a non-inverting Input end of a fourth comparator inside the four-way differential comparator chip U1 respectively.

A first pin Output2 of the four-way differential comparator chip U1 is connected with the right end of the eighth resistor R8; a second pin Output1 of the four-way differential comparator chip U1 is connected to the lower end of the fifth resistor R5, the right end of the fourth resistor R4 and the right end of the first capacitor C1; a third pin VCC of the four-way differential comparator chip U1 is connected to the right end of the third capacitor C3, the collector of the first triode Q1, the upper end of the first resistor R1, the upper end of the fifth resistor R5, the upper end of the seventh resistor R7, the upper end of the tenth resistor R10, the upper end of the twelfth resistor R12, the collector of the fourth triode Q4, and a power supply terminal; a fourth pin Input1 "of the four-way differential comparator chip U1 is connected to the right end of the first diode D1, the right end of the second capacitor C2, the right end of the sixth resistor R6, the lower end of the seventh resistor R7, and the left end of the eighth resistor R8, respectively; a fifth pin Input1+ of the four-way differential comparator chip U1 is respectively connected to a sixth pin Input2 "of the four-way differential comparator chip U1, a ninth pin Input 3" of the four-way differential comparator chip U1, and a tenth pin Input4 "of the four-way differential comparator chip U1, a lower end of the fourteenth resistor R14, an upper end of the fifteenth resistor R15 and an upper end of the fifth capacitor C5; a seventh pin Input2+ of the four-way differential comparator chip U1 is respectively connected with an eighth pin Input 3-of the four-way differential comparator chip U1 and a PWM signal Input end; an eleventh pin Input4+ of the four-way differential comparator chip U1 is respectively connected to the second diode D2, the left end of the fourth capacitor C4, the right end of the ninth resistor R9, the left end of the eleventh resistor R11, and the lower end of the tenth resistor R10; the twelfth pin GND of the four-way differential comparator chip U1 is connected with a ground terminal; a thirteenth pin Output4 of the four-way differential comparator chip U1 is respectively connected to the lower end of the twelfth resistor R12 and the left end of the thirteenth resistor R13; a fourteenth pin Output3 of the four-way differential comparator chip U1 is respectively connected to the left end of the ninth resistor R9; the emitter of the first triode Q1 is respectively connected with the collector of the second triode Q2 and the half-bridge circuit; the base electrode of the first triode Q1 is respectively connected with the lower end of the first resistor R1, the left end of the second resistor R2 and the base electrode of the second triode Q2; the emitter of the second triode Q2 is connected with the ground terminal; a collector of the third transistor Q3 is connected to the right end of the second resistor R2, and an emitter of the third transistor Q3 is connected to the lower end of the third resistor R3 and the ground terminal, respectively; the base electrode of the third triode Q3 is respectively connected with the left end of the first capacitor C1, the upper end of the third resistor R3 and the left end of the fourth resistor R4; the left end of the sixth resistor R6 is connected with the left end of the second capacitor C2 and the ground end; the upper end of the fourteenth resistor R14 is connected with a power supply terminal, and the lower end of the fifteenth resistor R15 is connected with the lower end of the fifth capacitor C5 and the ground terminal; the right end of the fourth capacitor C4 is connected with the right end of the eleventh resistor R11 and the ground end; the base electrode of the fourth triode Q4 is respectively connected with the right end of the thirteenth resistor R13 and the base electrode of the fifth triode Q5; the emitter of the fourth transistor Q4 is respectively the collector of the fifth transistor Q5 and the half-bridge circuit; an emitter of the fifth triode Q5 is connected with a ground terminal; the left end of the third capacitor C3 is connected to the ground terminal.

The input of drive module is PWM signal and benchmark comparison voltage Vcompare, switch tube connected on with the half-bridge circuit through output HO, switch tube connected under output LO and the half-bridge circuit, through the inside voltage comparator of feedback control module dual voltage comparator chip U2, if the battery joins conversely or output voltage value is too high, feedback control module feeds back the voltage comparison result to drive module, make drive module abnormal work, thereby reach the effect of follow-up electronic component such as protection switch tube.

Referring to fig. 3, the half-bridge circuit includes a sixth MOS transistor Q6, a seventh MOS transistor Q7, a first inductor L1, a twenty-seventh resistor R27, a twenty-eighth resistor R28, a twenty-ninth resistor R29, a thirty-third resistor R30, a thirty-first resistor R31, an eleventh capacitor C11, and a twelfth capacitor C12; the gate of the sixth MOS transistor Q6 is connected to the driving module and the upper end of the twenty-seventh resistor R27, the drain of the sixth MOS transistor Q6 is connected to the upper end of the twelfth capacitor C12 and the power supply terminal, respectively, and the source of the sixth MOS transistor Q6 is connected to the left end of the twenty-ninth resistor R29, the lower end of the twenty-seventh resistor R27, the drain of the seventh MOS transistor Q7 and the power supply terminal, respectively; the gate of the seventh MOS transistor Q7 is connected to the driving module and the upper end of the twenty-eighth resistor R28, respectively, and the source of the seventh MOS transistor Q7 is connected to the lower end of the twenty-eighth resistor R28, the upper end of the thirty-eighth resistor R30, the upper end of the thirty-first resistor R31, and the lower end of the eleventh capacitor C11, respectively; the lower end of the twelfth capacitor C12 is connected with the upper end of the eleventh capacitor C11 and the lower end of the first inductor L1; the right end of the twenty-ninth resistor R29 is connected with the upper end of the first inductor L1; the lower end of the thirty-third resistor R30 is connected with the lower end of the thirty-first resistor R31 and the ground terminal.

The feedback control module comprises a dual-voltage comparator chip U2, a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a twenty-second resistor R22, a twenty-third resistor R23, a twenty-fourth resistor R24, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10, a first diode D1 and a second diode D2; a first pin Output1, a second pin Input1 and a third pin Input1+ of the dual-voltage comparator chip U2 respectively correspond to an Output end, an inverting Input end and a non-inverting Input end of a first operational amplifier in the dual-voltage comparator chip U2; the seventh pin Output2, the sixth pin Input2 and the fifth pin Input2+ of the dual-voltage comparator chip U2 respectively correspond to an Output end, an inverting Input end and a non-inverting Input end of a second operational amplifier in the dual-voltage comparator chip U2.

A first pin Output1 of the dual-voltage comparator chip U2 is respectively connected with the upper end of the eighteenth resistor R18, the lower end of the twenty-sixth resistor R26, the cathode of the first diode D1, the cathode of the second diode D2, a seventh pin Output2 of the dual-voltage comparator chip U2 and the upper end of the twenty-first resistor R21; a second pin Input1 "of the dual-voltage comparator chip U2 is respectively connected to the lower end of the nineteenth resistor R19, the upper end of the twentieth resistor R20, the upper end of the sixth capacitor C6 and the upper end of the seventh capacitor C7; a third pin Input1+ of the dual-voltage comparator chip U2 is respectively connected to the right end of the sixteenth resistor R16, the lower end of the seventeenth resistor R17, the lower end of the eighteenth resistor R18 and the upper end of the tenth capacitor C10; a fifth pin Input2+ of the dual-voltage comparator chip U2 is respectively connected to the lower end of the twenty-first resistor R21, the upper end of the twenty-second resistor R22 and the left end of the twenty-third resistor R23; a sixth pin Input2 "of the dual-voltage comparator chip U2 is respectively connected to the upper end of the ninth capacitor C9, the upper end of the twenty-fourth resistor R24 and the left end of the twenty-fifth resistor R25; an eighth pin VDD of the dual-voltage comparator chip U2 is respectively connected with the left end of the eighth capacitor C8 and a power supply end; the upper end of the nineteenth resistor R19, the upper end of the seventeenth resistor R17, the right end of the twenty-third resistor R23 and the upper end of the twenty-sixth resistor R26 are respectively connected with power supply terminals; the left end of the sixteenth resistor R16 is connected with a load battery; the right end of the twenty-fifth resistor R25 is connected with the half-bridge circuit; the lower end of the twentieth resistor R20, the lower end of the sixth capacitor C6, the lower end of the tenth capacitor C10, the lower end of the seventh capacitor C7, the fourth pin GND of the dual-voltage comparator chip U2, the lower end of the twenty-second resistor R22, the right end of the eighth capacitor C8, the lower end of the ninth capacitor C9 and the lower end of the twenty-fourth resistor R24 are respectively connected to a ground terminal.

Preferably, the four-way differential comparator chip U1 is LM339 model.

Preferably, the dual voltage comparator chip U2 is model LM 393.

The driving module drives the half-bridge circuit of the switching power supply to supply power to the load battery, and the half-bridge circuit adopts a first MOS tube switching circuit and a second MOS tube switching circuit to avoid a half-conduction region; meanwhile, the feedback control module is used for collecting the voltages of the half-bridge circuit and the load battery to be compared, and the driving module controls whether the switching power supply is disconnected or not according to comparison data, so that the effect of protecting the whole circuit is achieved, the stable work of the switching power supply is facilitated, and the problems that the driving module is complex and components of the feedback control module are various and unstable are solved.

First, when the output voltage of the half-bridge circuit of the switching power supply rises, the voltage input terminal DCV of the feedback control module also rises, the voltage of the inverting input terminal of the second operational amplifier acting inside the dual-voltage comparator chip rises, the reference voltage of the non-inverting input terminal of the second operational amplifier is provided by the twenty-second resistor R22, the reference voltage is used for carrying out comparison operation with the voltage of the inverting input terminal of the second operational amplifier, and a high level is output at the output terminal due to the action of the pull-up resistor twenty-sixth resistor R26.

Then, when the load battery is connected positively (normal operation state), the voltage of the load battery voltage detection terminal BVC of the feedback control module is applied to the non-inverting input terminal of the first operational amplifier through the sixteenth resistor R16, the reference voltage of the inverting input terminal of the first operational amplifier is provided by the twenty-second resistor R20, the reference voltage is used for comparison operation with the voltage of the non-inverting input terminal of the first operational amplifier, and a high level is output at the output terminal due to the action of the pull-up resistor twenty-sixth resistor R26.

When the system works normally, two output ends of the dual-voltage comparator chip output high levels under the action of a twenty-sixth pull-up resistor R26; when the system does not work normally, (the voltage value of the voltage input end DCV is higher than the reference voltage value, the battery is reversely connected) the output end corresponding to the dual-voltage comparator chip outputs a low level after being operated by the internal amplifier, and the low level is fed back to the driving module, so that the level signal of the fourth pin or the eleventh pin of the four-way differential comparator chip is always in a low level state, the system stops working, and the components of the system are protected.

Finally, in this embodiment, the battery voltage detection and the voltage feedback (i.e., the first pin and the seventh pin in the four-way differential comparator chip) are fed back to the driving module in a parallel feedback manner, and the four-way differential comparator chip selects the operating mode according to the feedback signal to realize the stable output of the voltage.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.

Claims

1. The utility model provides a take protect function's switching power supply drive circuit which characterized in that: the method comprises the following steps: the device comprises a driving module, a half-bridge circuit, a load battery and a feedback control module; the feedback control module comprises a dual-voltage comparator chip;

the half-bridge circuit is respectively connected with the driving module and the load battery, and the feedback control module is respectively connected with the driving module, the half-bridge circuit and the load battery; the driving module is used for driving the half-bridge circuit to supply power to the load battery; the feedback control module is used for acquiring the voltage of the half-bridge circuit and the voltage of the load battery, comparing the acquired voltage data and feeding back the data to the driving module;

the half-bridge circuit comprises a first MOS tube switching circuit and a second MOS tube switching circuit, and the first MOS tube switching circuit and the second MOS tube switching circuit are alternately switched on;

the half-bridge circuit comprises a sixth MOS tube, a seventh MOS tube, a first inductor, a twenty-seventh resistor, a twenty-eighth resistor, a twenty-ninth resistor, a thirty-eighth resistor, a thirty-ninth resistor, an eleventh capacitor and a twelfth capacitor; a grid electrode of the sixth MOS transistor is connected to the driving module and the upper end of the twenty-seventh resistor respectively, a drain electrode of the sixth MOS transistor is connected to the upper end of the twelfth capacitor and the power supply end VOC respectively, and a source electrode of the sixth MOS transistor is connected to the left end of the twenty-ninth resistor, the lower end of the twenty-seventh resistor, the drain electrode of the seventh MOS transistor and the power supply end VS respectively; a grid electrode of the seventh MOS tube is respectively connected with the driving module and the upper end of the twenty-eighth resistor, and a source electrode of the seventh MOS tube is respectively connected with the lower end of the twenty-eighth resistor, the upper end of the thirtieth resistor, the upper end of the thirty-first resistor and the lower end of the eleventh capacitor; the lower end of the twelfth capacitor is connected with the upper end of the eleventh capacitor and the lower end of the first inductor; the right end of the twenty-ninth resistor is connected with the upper end of the first inductor; the lower end of the thirty-first resistor is connected with the lower end of the thirty-first resistor and a ground terminal;

the feedback control module comprises a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, a twenty-fourth resistor, a twenty-fifth resistor, a twenty-sixth resistor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, a first diode and a second diode; a first pin of the dual-voltage comparator chip is respectively connected with the upper end of the eighteenth resistor, the lower end of the twenty-sixth resistor, the cathode of the first diode, the cathode of the second diode, a seventh pin of the dual-voltage comparator chip and the upper end of the twenty-first resistor; a second pin of the dual-voltage comparator chip is respectively connected with the lower end of the nineteenth resistor, the upper end of the twentieth resistor, the upper end of the sixth capacitor and the upper end of the seventh capacitor; a third pin of the dual-voltage comparator chip is respectively connected with the right end of the sixteenth resistor, the lower end of the seventeenth resistor, the lower end of the eighteenth resistor and the upper end of the tenth capacitor; a fifth pin of the dual-voltage comparator chip is respectively connected with the lower end of the twenty-first resistor, the upper end of the twenty-second resistor and the left end of the twenty-third resistor; a sixth pin of the dual-voltage comparator chip is respectively connected with the upper end of the ninth capacitor, the upper end of the twenty-fourth resistor and the left end of the twenty-fifth resistor; an eighth pin of the dual-voltage comparator chip is respectively connected with the left end of the eighth capacitor and a power supply end VDD; the upper end of the nineteenth resistor, the upper end of the seventeenth resistor, the right end of the twenty-third resistor and the upper end of the twenty-sixth resistor are respectively connected with a power supply end VDD; the left end of the sixteenth resistor is connected with a load battery; the anode of the first diode is connected with a fourth pin of a four-way differential comparator chip in the driving module, and the anode of the second diode is connected with an eleventh pin of the four-way differential comparator chip in the driving module; the right end of the twenty-fifth resistor is a voltage input end DCV of the feedback control module, the voltage input end DCV is connected with the half-bridge circuit, and when the output voltage of the half-bridge circuit of the switching power supply rises, the voltage of the voltage input end DCV of the feedback control module also rises; the lower end of the twentieth resistor, the lower end of the sixth capacitor, the lower end of the tenth capacitor, the lower end of the seventh capacitor, a fourth pin of the dual-voltage comparator chip, the lower end of the twenty-second resistor, the right end of the eighth capacitor, the lower end of the ninth capacitor and the lower end of the twenty-fourth resistor are respectively connected with a ground terminal;

the driving module comprises a four-way differential comparator chip, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a first triode, a second triode, a third triode, a fourth triode, a fifth triode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor and a fifth capacitor; a first pin of the four-way differential comparator chip is connected with the right end of the eighth resistor; a second pin of the four-way differential comparator chip is connected with the lower end of the fifth resistor, the right end of the fourth resistor and the right end of the first capacitor; a third pin of the four-way differential comparator chip is connected to the right end of the third capacitor, the collector of the first triode, the upper end of the first resistor, the upper end of the fifth resistor, the upper end of the seventh resistor, the upper end of the tenth resistor, the upper end of the twelfth resistor, the collector of the fourth triode, and a power supply end VDD; a fourth pin of the four-way differential comparator chip is respectively connected with the anode of the first diode, the right end of the second capacitor, the right end of the sixth resistor, the lower end of the seventh resistor and the left end of the eighth resistor in the feedback control module; a fifth pin of the four-way differential comparator chip is respectively connected with a sixth pin of the four-way differential comparator chip, a ninth pin of the four-way differential comparator chip, a tenth pin of the four-way differential comparator chip, a lower end of the fourteenth resistor, an upper end of the fifteenth resistor and an upper end of the fifth capacitor; the seventh pin of the four-way differential comparator chip is respectively connected with the eighth pin of the four-way differential comparator chip and the PWM signal input end; an eleventh pin of the four-way differential comparator chip is respectively connected with an anode of a second diode in the feedback control module, a left end of the fourth capacitor, a right end of the ninth resistor, a left end of the eleventh resistor and a lower end of the tenth resistor; the twelfth pin of the four-way differential comparator chip is connected with a ground terminal; a thirteenth pin of the four-way differential comparator chip is respectively connected with the lower end of the twelfth resistor and the left end of the thirteenth resistor; a fourteenth pin of the four-way differential comparator chip is connected with the left end of the ninth resistor; an emitting electrode of the first triode is respectively connected with an emitting electrode of the second triode and the upper end of a twenty-seventh resistor in the half-bridge circuit; the base electrode of the first triode is respectively connected with the lower end of the first resistor, the left end of the second resistor and the base electrode of the second triode; the collector of the second triode is connected with a grounding terminal; a collector of the third triode is connected with the right end of the second resistor, and an emitter of the third triode is respectively connected with the lower end of the third resistor and a ground terminal; the base electrode of the third triode is respectively connected with the left end of the first capacitor, the upper end of the third resistor and the left end of the fourth resistor; the left end of the sixth resistor is connected with the left end of the second capacitor and the grounding end; the upper end of the fourteenth resistor is connected with a power supply end VDD, and the lower end of the fifteenth resistor is connected with the lower end of the fifth capacitor and a ground end; the right end of the fourth capacitor is connected with the right end of the eleventh resistor and the ground end; the base electrode of the fourth triode is respectively connected with the right end of the thirteenth resistor and the base electrode of the fifth triode; an emitter of the fourth triode is respectively connected with an emitter of the fifth triode and the upper end of a twenty-eighth resistor of the half-bridge circuit; and the collector of the fifth triode is connected with the ground terminal.

2. The switching power supply driving circuit with the protection function according to claim 1, wherein: the model of the four-way differential comparator chip is LM 339.

3. The switching power supply driving circuit with the protection function according to claim 1, wherein: the dual voltage comparator chip is LM 393.