Load driving circuit based on power electronic switch

Abstract

The utility model provides a load driving circuit based on a power electronic switch, which belongs to the technical field of load circuits and comprises an electronic switch circuit and a Schottky diode circuit, the electronic switch circuit comprises a high-side switch U17, a plurality of resistors, a BJT transistor, an NPN transistor, two freewheel diodes, a capacitor and a detection resistor, the output end of the high-side switch U17 is connected with the positive electrode of the load, and the input end of the high-side switch U17 is connected with the power supply. According to the utility model, the MCU sends out a signal according to a control requirement, the power electronic switch receives the signal and then judges whether to conduct the circuit, and when the circuit is conducted, current drives the load through the power electronic switch; when the power electronic switch is turned off, the current is subjected to follow current through the Schottky diode D43, voltage spikes and circuit damage are avoided, the Schottky diode D43 provides a follow current loop when the power electronic switch is turned off, continuity of load current is ensured, energy loss and electromagnetic interference in the circuit are reduced, and voltage spikes and circuit damage are avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to load circuit technical field, specifically, it relates to a kind of load driving circuit based on power electronic switch. BACKGROUND

[0002] In modern industry and electronic equipment, how to efficiently drive various loads is a key problem, and power electronic switch, as a kind of electronic device capable of quickly controlling power on-off and conversion, provides a new way for the design and optimization of load driving circuit. The load driving circuit based on power electronic switch emerges as the times require, which utilizes the characteristics of power electronic switch to realize precise control of the load and improve the efficiency of power utilization.

[0003] In the prior art, the traditional load driving circuit has the problems of slow response speed, high power consumption and low reliability, and it is difficult to meet the high-precision and high-efficiency control requirements of special robots in complex environments, and the reliability of the system is low. How to invent a load driving circuit based on power electronic switch to solve these problems has become a problem to be solved by the technical personnel in the field. UTILITY MODEL CONTENTS

[0004] In order to make up for the above shortcomings, the utility model provides a load driving circuit based on power electronic switch, which aims to solve the problem of low reliability of the traditional load driving circuit.

[0005] The utility model is realized as follows:

[0006] The utility model provides a load driving circuit based on power electronic switch, which comprises an electronic switch circuit and a Schottky diode circuit, the electronic switch circuit comprises a high-side switch U17, resistors R88, R89, R90, R91, R92, a BJT transistor, an NPN transistor, freewheeling diodes D34 and BAV199 and a capacitor C62, the output end of the high-side switch U17 is connected with the positive electrode of the load, and the input end of the high-side switch U17 is connected with the power supply.

[0007] The Schottky diode circuit comprises a plurality of parallel Schottky diodes D43, and the input end of the Schottky diode circuit is connected with the output end of the electronic switch circuit.

[0008] Preferably, the pin 2 of the high-side switch U17 is connected with the collector of the NPN transistor, and the resistor R88 is connected in series between the pin 2 of the high-side switch U17 and the collector of the NPN transistor.

[0009] Preferably, the base of the NPN transistor and the collector of the BJF transistor are connected, the emitter of the NPN is grounded, the base of the BJF transistor and one end of the resistor R89 are connected, the other end of the resistor R89 and the output end of the PWM signal are connected, the emitter of the BJF and one end of the resistor R91 are connected, and the other end of the resistor R91 is connected to the ground.

[0010] Preferably, the output end of the freewheeling diode D34 is grounded, the input end of the freewheeling diode D34 is connected to the pin 4 of the high-side switch U17, the output end of the freewheeling diode BAV199 is connected to the input end of the freewheeling diode D34, the input end of the freewheeling diode BAV199 is connected to the power supply, and the freewheeling diode BAV199 is connected in parallel across the load.

[0011] Preferably, the input end of the capacitor C62 is connected to the pin 4 of the high-side switch U17, the output end of the capacitor C62 is connected to the ground, the two ends of the resistor R90 are connected to the input end of C62 and the pin 4 of the high-side switch U17 respectively, the pin 4 of the high-side switch U17 is connected to the resistor R92, and one end of the resistor R92 is grounded.

[0012] Preferably, a plurality of the Schottky diodes D43 are connected in parallel across the load, the anode of the Schottky diode D43 is connected to the OUT port of the high-side switch U17, and the cathode of the Schottky diode D43 is connected to the negative electrode of the load.

[0013] The utility model discloses the beneficial effect is:

[0014] The MCU sends a signal according to the control requirement, and the power electronic switch judges whether the circuit is turned on after receiving the signal, when the circuit is turned on, the current drives the load through the power electronic switch, when the circuit is turned off, the current flows through the Schottky diode D43, so as to avoid voltage peak and circuit damage, the Schottky diode D43 is arranged to provide a freewheeling circuit when the power electronic switch is turned off, so as to ensure the continuity of the load current, reduce the energy loss and electromagnetic interference in the circuit, avoid voltage peak and circuit damage, and improve the reliability of the system. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will be briefly introduced to the drawings needed to be used in the embodiment, and it should be understood that the following drawings only show some embodiments of the utility model, and should not be regarded as the limitation to the scope, and for the ordinary skilled person in the art, other related drawings can be obtained according to these drawings without the creative labor.

[0016] Fig. 1It is a kind of load driving circuit flow schematic diagram based on power electronic switch that the utility model embodiment provides;

[0017] Fig. 2 It is a kind of load driving circuit power electronic switch circuit principle diagram based on power electronic switch that the utility model embodiment provides;

[0018] Fig. 3 It is a kind of load driving circuit in the utility model embodiment based on power electronic switch Schottky diode circuit diagram. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical scheme and advantage of the utility model embodiment more clear, the technical scheme in the utility model embodiment will be clearly and completely described below with the drawings in the utility model embodiment, obviously, the described embodiment is a part of the utility model embodiment, instead of all the embodiment. Based on the embodiment in the utility model, all other embodiments obtained by the ordinary skill in the art without making creative labor are within the protection scope of the utility model.

[0020] Embodiment, refer to Figs. 1-3 A kind of load driving circuit based on power electronic switch, including electronic switch circuit and Schottky diode circuit, electronic switch circuit includes high side switch U17, resistance R88, resistance R89, resistance R90, resistance R91, resistance R92, BJT transistor, NPN transistor, freewheeling diode D34, freewheeling diode BAV199 and capacitor C62, the output of high side switch U17 and the anode of load are connected, and the input of high side switch U17 and power supply are connected;

[0021] Schottky diode circuit includes multiple parallel Schottky diodes D43, and the input of Schottky diode circuit is connected with the output of electronic switch circuit.

[0022] Further; the pin 2 of the high-side switch U17 and the collector of the NPN transistor are connected, a resistor R88 is connected in series between the pin 2 of the high-side switch U17 and the collector of the NPN transistor, the base of the NPN transistor and the collector of the BJF transistor are connected, the emitter of the NPN is grounded, the base of the BJF transistor and one end of the resistor R89 are connected, the other end of the resistor R89 and the output terminal of the PWM signal are connected, the emitter of the BJF and one end of the resistor R91 are connected, the other end of the resistor R91 is connected to the ground, the output terminal of the freewheeling diode D34 is grounded, the input terminal of the freewheeling diode D34 is connected to the pin 4 of the high-side switch U17, the output terminal of the freewheeling diode BAV199 is connected to the input terminal of the freewheeling diode D34, the input terminal of the freewheeling diode BAV199 is connected to the power supply, the freewheeling diode BAV199 is connected in parallel to the load, the input terminal of the capacitor C62 is connected to the pin 4 of the high-side switch U17, the output terminal of the capacitor C62 is connected between the ground, the two ends of the resistor R90 are respectively connected to the input terminal of C62 and the pin 4 of the high-side switch U17, the pin 4 of the high-side switch U17 is connected to the resistor R92, one end of the resistor R92 is grounded, a plurality of Schottky diodes D43 are connected in parallel across the load, the anode of the Schottky diode D43 is connected to the OUT port of the high-side switch U17, and the cathode of the Schottky diode D43 is connected to the negative electrode of the load.

[0023] It should be noted that:

[0024] The MCU micro control unit is connected with the electronic switch circuit, and the output terminal of the electronic switch circuit is connected with the input terminal of the Schottky diode circuit. The PWM3 signal is amplified through the resistor network and the transistor (Q17 and MMBT555), and then drives the BTS6143D high-side switch U17. The BTS6143D controls the power supply of the load according to the PWM signal, so as to adjust the power output of the load. When the BTS6143D is turned off, the freewheeling diode (D34 and BAV199) provides a freewheeling circuit to prevent high voltage generated by the inductive load from damaging the power electronic switch. The freewheeling circuit provided by the power electronic switch ensures the stability and reliability of the circuit. Through the cooperation of the power electronic switch and the Schottky diode D43, the energy loss in the circuit is reduced, and the overall efficiency of the system is improved. Through the fast conduction and turn-off characteristics of the power electronic switch, the fast response of the load is ensured, which is suitable for high-precision control scenes. The freewheeling circuit provided by the Schottky diode D43 avoids voltage spikes and circuit damage, and improves the reliability of the system.

[0025] The high-side switch U17 adopts a BTS6143D high-side power switch for controlling a high-current load, and a resistor connected between the PWM signal and the BJF transistor Q7 is used for current limiting and voltage regulation to avoid excessive current in the circuit affecting the function, and the resistor connected in series between the high-side switch U17 and the NPN ensures that the signal remains stable without input, and the resistor connected between the BJF transistor Q7 and the ground is used for current limiting or voltage division of the circuit, and the freewheeling diode D34 provides a freewheeling circuit for the circuit, and the freewheeling diode BAV199 is used to prevent reverse voltage from damaging the circuit;

[0026] The working principle of the load driving circuit based on the power electronic switch is as follows:

[0027] The MCU sends a signal according to the control requirement, and the power electronic switch judges whether to turn on the circuit after receiving the signal, when turned on, the current drives the load through the power electronic switch, and when turned off, the current flows through the Schottky diode D43 to avoid voltage spikes and damage to the Schottky diode D43, and to prevent high voltage generated by the inductive load from damaging the power electronic switch, the Schottky diode D43 provides a freewheeling circuit for the power electronic switch, ensuring the stability and reliability of the circuit, the cooperation of the power electronic switch and the Schottky diode D43 reduces the energy loss in the circuit, improves the overall efficiency of the system, and the fast turn-on and turn-off characteristics of the power electronic switch ensure the fast response of the load, which is suitable for high-precision control scenarios, and the freewheeling circuit provided by the Schottky diode D43 avoids voltage spikes and circuit damage.

[0028] The above only describes preferred embodiments of the present application and is not intended to limit the present application, and for those skilled in the art, the present application can be variously changed and modified. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A power electronic switch based load driving circuit comprising an electronic switch circuit and a Schottky diode circuit, characterized in that, The electronic switch circuit includes high side switch U17, resistor R88, resistor R89, resistor R90, resistor R91, resistor R92, BJT transistor, NPN transistor, freewheeling diode D34, freewheeling diode BAV199 and capacitor C62, the output of the high side switch U17 is connected with the positive pole of the load, and the input of the high side switch U17 is connected with the power supply; The Schottky diode circuit includes a plurality of parallel Schottky diodes D43, the input of the Schottky diode circuit is connected with the output of the electronic switch circuit.

2. A power electronic switch based load driving circuit according to claim 1, characterized in that, The pin 2 of the high side switch U17 is connected with the collector of the NPN transistor, and the resistor R88 is connected in series between the pin 2 of the high side switch U17 and the collector of the NPN transistor.

3. A power electronic switch based load driving circuit according to claim 2, characterized in that, The base of the NPN transistor is connected with the collector of the BJF transistor, the emitter of the NPN is grounded, the base of the BJF transistor is connected with one end of the resistor R89, the other end of the resistor R89 is connected with the output of the PWM signal, the emitter of the BJF is connected with one end of the resistor R91, and the other end of the resistor R91 is connected to the ground.

4. A power electronic switch based load driving circuit according to claim 3, characterized in that, The output of the freewheeling diode D34 is grounded, the input of the freewheeling diode D34 is connected with the pin 4 of the high side switch U17, the output of the freewheeling diode BAV199 is connected with the input of the freewheeling diode D34, the input of the freewheeling diode BAV199 is connected with the power supply, and the freewheeling diode BAV199 is connected in parallel between the two ends of the load.

5. A power electronic switch based load driving circuit according to claim 4, characterized in that, The input of the capacitor C62 is connected with the pin 4 of the high side switch U17, the output of the capacitor C62 is connected between the ground, the two ends of the resistor R90 are respectively connected with the input of the C62 and the pin 4 of the high side switch U17, the pin 4 of the high side switch U17 is connected with the resistor R92, and one end of the resistor R92 is grounded.

6. A power electronic switch based load driving circuit according to claim 5, characterized in that, A plurality of the Schottky diodes D43 are connected in parallel between the two ends of the load, the anode of the Schottky diode D43 is connected with the OUT port of the high side switch U17, and the cathode of the Schottky diode D43 is connected with the negative pole of the load.

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