High-side driving circuit with over-temperature protection

Abstract

The utility model belongs to the technical field of high-side driving circuits, and particularly discloses a high-side driving circuit with over-temperature protection, which comprises a PMOS (P-channel Metal Oxide Semiconductor) tube M1, a divider resistor R2, a divider resistor R3, a resistor R6, an NTC (Negative Temperature Coefficient) thermosensitive resistor and an NPN type triode Q1, the G pole of the PMOS tube M1 is connected with one end of the divider resistor R2, the other end of the divider resistor R2 is connected with the S pole of the PMOS tube M1 and one end of the divider resistor R3, and the other end of the divider resistor R6 is connected with the other end of the NPN type triode Q1. The D pole of the PMOS transistor M1 is connected with a high-side driving output end; the other end of the divider resistor R3 is connected with the collector electrode of the NPN type triode Q1, and the base electrode of the NPN type triode Q1 is connected with one end of the resistor R6 and one end of the NTC thermosensitive resistor. The high-side driving circuit with the over-temperature protection function is realized, the function of an imported chip is achieved through combination of domestic devices, the circuit is simplified, and the maintainability of the circuit is improved.

Description

Technical Field

[0001] This utility model relates to the field of high-side drive circuit technology, specifically a high-side drive circuit with over-temperature protection. Background Technology

[0002] A high-side drive circuit is a circuit used to drive power devices (such as power transistors, MOSFETs, etc.). It can control the power devices to turn on and off on the high-voltage side (relative to the ground terminal) and is widely used in automotive electronics, industrial control, power management and other fields.

[0003] The core of a high-side drive circuit is to control the gate (for MOSFETs) or base (for transistors) voltage of a power device using a control signal, thereby controlling the device's on / off state. In high-side drive, the source (for MOSFETs) or emitter (for transistors) of the power device is connected to the high end of the load, while the drain (for MOSFETs) or collector (for transistors) is connected to the positive terminal of the power supply. By controlling the gate or base voltage of the power device to be higher than a certain threshold value of the source or emitter voltage, the power device will conduct, allowing current to flow from the positive terminal of the power supply through the power device to the load; when the gate or base voltage is lower than the threshold value, the power device will turn off, cutting off the current path.

[0004] Some current high-side drive circuits have the following defects: some high-side drive circuits lack protection functions, some high-side drive circuits are complex, and some high-side drive circuits are inconvenient to repair. Utility Model Content

[0005] The purpose of this invention is to provide a high-side drive circuit with over-temperature protection to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a high-side drive circuit with over-temperature protection, comprising:

[0007] PMOS transistor M1, voltage divider resistor R2, voltage divider resistor R3, resistor R6, NTC thermistor, NPN transistor Q1;

[0008] Wherein, the gate of the PMOS transistor M1 is connected to one end of the voltage divider resistor R2, the other end of the voltage divider resistor R2 is connected to the source of the PMOS transistor M1 and one end of the voltage divider resistor R3, and the drain of the PMOS transistor M1 is connected to the high-side drive output terminal.

[0009] The other end of the voltage divider resistor R3 is connected to the collector of the NPN transistor Q1. The base of the NPN transistor Q1 is connected to one end of the resistor R6 and one end of the NTC thermistor. The other end of the resistor R6 is connected to the high-side drive enable port. The other end of the NTC thermistor is connected to the emitter of the NPN transistor Q1.

[0010] Preferably, the resistance values ​​of the voltage divider resistors R2 and R3 are 1MΩ.

[0011] Preferably, the resistance of resistor R6 is 10KΩ.

[0012] Preferably, the resistance of the NTC thermistor is 10KΩ at 25 degrees Celsius.

[0013] Preferably, the high-side drive enable port is an MCU drive enable port with an enable level of 5V.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] A high-side drive circuit with over-temperature protection is implemented, achieving the functionality of imported chips by combining domestically produced components, thus simplifying the circuit and increasing its maintainability. Attached Figure Description

[0016] Figure 1 This is a high-side drive circuit diagram with over-temperature protection for this utility model. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0019] Example 1:

[0020] Please see Figure 1This utility model provides a technical solution: a high-side drive circuit with over-temperature protection, comprising: a PMOS transistor M1, a voltage divider resistor R2, a voltage divider resistor R3, a resistor R6, an NTC thermistor, and an NPN transistor Q1.

[0021] In this configuration, the gate (G) of PMOS transistor M1 is connected to one end of voltage divider resistor R2, the other end of voltage divider resistor R2 is connected to the source (S) of PMOS transistor M1 and one end of voltage divider resistor R3, and the drain (D) of PMOS transistor M1 is connected to the high-side drive output terminal; the other end of voltage divider resistor R3 is connected to the collector of NPN transistor Q1, the base of NPN transistor Q1 is connected to one end of resistor R6 and one end of NTC thermistor, the other end of resistor R6 is connected to the high-side drive enable port, and the other end of NTC thermistor is connected to the emitter of NPN transistor Q1.

[0022] Analysis of the above: A high-side drive circuit with over-temperature protection is constructed using discrete components such as resistors, P-type MOSFETs (PMOS transistor M1), NTC thermistors, and NPN transistors Q1. Based on this high-side drive circuit with over-temperature protection, a high-side drive circuit with over-temperature protection function is realized; the functionality of imported chips is achieved by combining domestically produced components; the circuit is simplified; and the circuit maintainability is increased.

[0023] Example 2:

[0024] Please see Figure 1 This utility model provides a technical solution based on Embodiment 1: the resistance values ​​of the voltage divider resistors R2 and R3 are 1MΩ. The resistance value of the resistor R6 is 10KΩ. At 25 degrees Celsius, the resistance value of the NTC thermistor is 10KΩ. The high-side drive enable port is the MCU drive enable port, and the enable level is 5V.

[0025] Analysis of the above: In the attached diagram, M1 is a PMOS transistor. The high-side drive output is the external output port of this circuit. R2 and R3 in the diagram are 1MΩ voltage divider resistors between the gate (G) and source (S) terminals of M1. When one end of R3 is grounded through Q1, M1 conducts, and the high-side drive output can output voltage. Q1 in the diagram is an NPN transistor. Q1 conducts when the voltage at pin 1 is greater than 0.7V. The NTC thermistor and resistor R6 in the diagram are voltage divider resistors on the base of Q1. The resistance of the NTC thermistor decreases with increasing temperature; at 25 degrees Celsius, the NTC resistance is 10KΩ. R6 is also a 10KΩ resistor.

[0026] The high-side drive enable port is the MCU drive enable port, with an enable level of 5V. Since the voltage of the high-side drive enable port is 5V, the voltage at pin 1 of Q1 equals the high-side drive enable port voltage multiplied by NTC, which is then divided by (R6 + NTC). When the voltage at pin 1 of Q1 is 0.7V, the resistance of NTC is approximately 1.628KΩ. Therefore, when the temperature rises and the NTC resistance reaches 1.628KΩ, the voltage at pin 1 of Q1 will be less than 0.7V. At this point, Q1 is disconnected, thus M1 is disconnected, and the high-side drive output is 0V.

[0027] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It is obvious to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description. Therefore, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this utility model, and no reference numerals in the claims should be considered as limiting the scope of the claims.

[0028] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-side drive circuit with over-temperature protection, characterized in that, include: PMOS transistor M1, voltage divider resistor R2, voltage divider resistor R3, resistor R6, NTC thermistor, NPN transistor Q1; Wherein, the gate of the PMOS transistor M1 is connected to one end of the voltage divider resistor R2, the other end of the voltage divider resistor R2 is connected to the source of the PMOS transistor M1 and one end of the voltage divider resistor R3, and the drain of the PMOS transistor M1 is connected to the high-side drive output terminal. The other end of the voltage divider resistor R3 is connected to the collector of the NPN transistor Q1. The base of the NPN transistor Q1 is connected to one end of the resistor R6 and one end of the NTC thermistor. The other end of the resistor R6 is connected to the high-side drive enable port. The other end of the NTC thermistor is connected to the emitter of the NPN transistor Q1.

2. The high-side drive circuit with over-temperature protection according to claim 1, characterized in that: The resistance values ​​of the voltage divider resistors R2 and R3 are 1MΩ.

3. The high-side drive circuit with over-temperature protection according to claim 1, characterized in that: The resistance of resistor R6 is 10KΩ.

4. A high-side drive circuit with over-temperature protection according to claim 1, characterized in that: At 25 degrees Celsius, the resistance of the NTC thermistor is 10KΩ.

5. A high-side drive circuit with over-temperature protection according to claim 1, characterized in that: The high-side drive enable port is the MCU drive enable port, and the enable level is 5V.

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