Under-voltage protection system of driving chip

Abstract

The utility model discloses an under-voltage protection system of a driving chip, which comprises a power supply sampling loop, a trigger loop, an output driving loop and a control loop, the power supply sampling loop, the trigger loop, the output driving loop and the control loop are sequentially connected, and the power supply sampling loop is respectively connected with the output driving loop and the control loop. The power supply sampling loop is used for monitoring an input power supply voltage value and is connected to the trigger loop through devices such as a voltage stabilizing diode and the like, and the output driving loop is used for disconnecting and connecting a working power supply through the control loop according to a comparison result output by the trigger loop. The undervoltage protection circuit has the advantages of small influence on a power supply post-stage circuit part, simple and reliable circuit structure, high undervoltage protection control precision and stable performance, and solves the problems of low precision, high cost and the like existing in a common undervoltage protection scheme.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuit technology, specifically to an undervoltage protection system for a driver chip. Background Technology

[0002] Currently, most undervoltage protection circuit designs for driver chips are based on voltage comparators. Others convert the power supply voltage signal into a current signal and compare it with a reference current source, then use the comparison result to implement undervoltage protection. However, both of these approaches share certain characteristics, such as low control accuracy, susceptibility to environmental factors like temperature drift, and the need for an external power supply and reference voltage / current source. Furthermore, the poor temperature characteristics of the circuit can easily affect accuracy and performance. Therefore, this paper proposes an undervoltage protection system for driver chips to address these issues. Utility Model Content

[0003] To address the problems mentioned above, the present invention provides the following technical solution: an undervoltage protection system for a driver chip, comprising a power sampling circuit, a trigger circuit, an output drive circuit, and a control circuit, wherein the power sampling circuit, trigger circuit, output drive circuit, and control circuit are connected sequentially, and the power sampling circuit is also connected to the output drive circuit and the control circuit respectively. The power sampling circuit is used to monitor the input power voltage value and is connected to the trigger circuit through devices such as a Zener diode. The output drive circuit, based on the result of comparing the output of the trigger circuit, disconnects and connects the operating power supply through the control circuit.

[0004] As a preferred technical solution of this utility model, the power sampling circuit includes a monitoring power supply Vcc, a voltage divider resistor R1, a voltage divider resistor R2, and a capacitor C1. The monitoring power supply Vcc, the voltage divider resistor R1, and the voltage divider resistor R2 are connected in series, and the capacitor C1 is connected in parallel across the voltage divider resistor R2.

[0005] As a preferred embodiment of this utility model, the trigger circuit includes a Zener diode D1, a voltage divider resistor R3, a transistor Q1, and a voltage divider resistor R4. The Zener diode D1 is connected in series with the voltage divider resistor R3. The transistor Q1 is connected to both the voltage divider resistor R3 and the voltage divider resistor R4. The voltage divider resistor R4 is connected to the monitoring power supply Vcc via a wire. One end of the transistor Q1 is connected to the capacitor C1 via a wire.

[0006] As a preferred embodiment of this utility model, the output drive circuit includes a Zener diode D2, a voltage divider resistor R5, a voltage divider resistor R6, and a transistor Q2. The Zener diode D2, the voltage divider resistor R5, and the voltage divider resistor R6 are connected in series. The voltage divider resistor R5 and the voltage divider resistor R6 are connected to the transistor Q1 through a wire. The voltage divider resistor R6 is connected to the transistor Q2.

[0007] As a preferred embodiment of this utility model, the control circuit includes a Zener diode D3, a voltage divider resistor R7, a voltage divider resistor R8, a capacitor C2, and a MOSFET Q3. One end of the Zener diode D3 is connected to the transistor Q2, and the other end of the Zener diode D3 is connected to the transistor Q1. The voltage divider resistor R7 is connected to the transistor Q2. The voltage divider resistor R7, the voltage divider resistor R8, and the capacitor C2 are connected in series. The MOSFET Q3 is connected to the monitoring power supply Vcc and the capacitor C2.

[0008] As a preferred embodiment of this invention, the output drive circuit is used for undervoltage signal output, and the control circuit supplies voltage V2.

[0009] This utility model has the following advantages: Through the improved undervoltage protection circuit, the circuit involves sampling circuit, trigger circuit, and logic control output circuit. The circuit design mainly uses common discrete components such as transistors and Zener diodes, which not only makes the circuit design simple, but also makes it easy to debug and maintain, and has low cost. At the same time, the use of discrete components can improve the reliability and anti-interference of undervoltage protection, and can operate in environments with relatively harsh electromagnetic environments. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the operating principle of the undervoltage protection system according to a preferred embodiment of the present invention;

[0011] Figure 2 This is a circuit diagram of an undervoltage protection system according to a preferred embodiment of the present invention. Detailed Implementation

[0012] The technical solutions in the embodiments of this utility model are described clearly and completely below. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can also be implemented in other ways different from those described herein. Therefore, the scope of protection of this utility model is not limited to the specific embodiments disclosed below.

[0013] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0014] The present invention will be further described below with reference to the accompanying drawings.

[0015] Please refer to Figure 1-Figure 2 This utility model discloses an undervoltage protection system for a driver chip, comprising: a power sampling circuit, a trigger circuit, an output drive circuit, and a control circuit, which are connected in sequence. The power sampling circuit is also connected to the output drive circuit and the control circuit. The power sampling circuit is used to monitor the input power supply voltage value and is connected to the trigger circuit through devices such as Zener diodes. The output drive circuit disconnects and connects the working power supply through the control circuit based on the result of comparing the output of the trigger circuit.

[0016] The power sampling circuit includes a monitoring power supply Vcc, voltage divider resistors R1 and R2, and a capacitor C1. The monitoring power supply Vcc, voltage divider resistors R1 and R2 are connected in series, and the capacitor C1 is connected in parallel across the voltage divider resistor R2. The trigger circuit includes a Zener diode D1, a voltage divider resistor R3, a transistor Q1, and a voltage divider resistor R4. The Zener diode D1 is connected in series with the voltage divider resistor R3, and the transistor Q1 is connected to both the voltage divider resistors R3 and R4. The voltage divider resistor R4 is connected to the monitoring power supply Vcc through a wire, and one end of the transistor Q1 is connected to the capacitor C1 through a wire.

[0017] The output drive circuit includes a Zener diode D2, voltage divider resistors R5 and R6, and a transistor Q2. The Zener diode D2, voltage divider resistors R5 and R6 are connected in series. Voltage divider resistors R5 and R6 are connected to transistor Q1 via a wire. Voltage divider resistor R6 is connected to transistor Q2. The control circuit includes a Zener diode D3, voltage divider resistors R7 and R8, a capacitor C2, and a MOSFET Q3. One end of the Zener diode D3 is connected to transistor Q2, and the other end of the Zener diode D3 is connected to transistor Q1. Voltage divider resistor R7 is connected to transistor Q2. Voltage divider resistors R7, R8, and capacitor C2 are connected in series. MOSFET Q3 is connected to the monitoring power supply Vcc and capacitor C2 respectively. The output drive circuit is used for undervoltage signal output, and the control circuit supplies voltage V2.

[0018] Specifically, in use, the Zener diode D1 is connected to the trigger control transistor Q1. Adjusting the parameters of the voltage divider resistors R1 and R2, and the Zener diode D1, allows the circuit threshold value to be determined. Transistor Q1 is connected to the base of the driving transistor Q1 via the Zener diode D2, current-limiting and voltage-dividing resistors R5 and R6. When the trigger transistor Q1 is turned on, meaning the monitored power supply voltage is within acceptable limits, the driving transistor Q2 is turned on. The power supply passes through transistor Q2, then through the current-limiting and voltage-dividing resistors R7 and R8, driving the MOSFET field-effect transistor Q3 to turn on, outputting voltage V2, which can power the load. When the power supply voltage is lower than the set threshold voltage, the voltage output by the sampling circuit is lower than the Zener diode D1. When the Zener diode D1 is turned on, the Zener diode D1 is turned off, directly putting the transistor in the off state. Consequently, neither the subsequent drive circuit nor the control circuit will conduct, and the load circuit will not work when power is lost. The undervoltage protection threshold can be controlled by adjusting the parameters of the Zener diode D1 and the voltage divider resistor R3. Using the transistor Q2 to drive the subsequent control circuit can improve the driving capability and sensitivity. The MOSFET field-effect transistor Q3 serves as the main unit of the control circuit, which can further reduce the internal resistance of the power supply circuit. The charging and discharging of capacitors C1 and C2 can effectively prevent power supply jitter from damaging the power circuit or chip. Therefore, this circuit design is simple in structure, does not require an auxiliary power supply or a reference power supply, and can effectively detect the power supply status of the load.

[0019] The above are merely preferred embodiments of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.

[0020] All other parts of this utility model that are not described in detail belong to the prior art, and therefore will not be described in detail here.

[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An undervoltage protection system for a driver chip, characterized in that, include: The system includes a power sampling circuit, a trigger circuit, an output drive circuit, and a control circuit, which are connected in sequence. The power sampling circuit is also connected to the output drive circuit and the control circuit. The power sampling circuit is used to monitor the input power voltage value and is connected to the trigger circuit through devices such as Zener diodes. The output drive circuit disconnects and connects the working power supply through the control circuit based on the result of comparing the output of the trigger circuit.

2. The undervoltage protection system for a driver chip as described in claim 1, characterized in that, The power sampling circuit includes a monitoring power supply Vcc, a voltage divider resistor R1, a voltage divider resistor R2, and a capacitor C1. The monitoring power supply Vcc, the voltage divider resistor R1, and the voltage divider resistor R2 are connected in series, and the capacitor C1 is connected in parallel across the voltage divider resistor R2.

3. The undervoltage protection system for a driver chip as described in claim 1, characterized in that, The trigger circuit includes a Zener diode D1, a voltage divider resistor R3, a transistor Q1, and a voltage divider resistor R4. The Zener diode D1 is connected in series with the voltage divider resistor R3. The transistor Q1 is connected to both the voltage divider resistor R3 and the voltage divider resistor R4. The voltage divider resistor R4 is connected to the monitoring power supply Vcc via a wire. One end of the transistor Q1 is connected to the capacitor C1 via a wire.

4. The undervoltage protection system for a driver chip as described in claim 1, characterized in that, The output drive circuit includes a Zener diode D2, a voltage divider resistor R5, a voltage divider resistor R6, and a transistor Q2. The Zener diode D2, the voltage divider resistor R5, and the voltage divider resistor R6 are connected in series. The voltage divider resistor R5 and the voltage divider resistor R6 are connected to the transistor Q1 through a wire. The voltage divider resistor R6 is connected to the transistor Q2.

5. The undervoltage protection system for a driver chip as described in claim 1, characterized in that, The control circuit includes a Zener diode D3, a voltage divider resistor R7, a voltage divider resistor R8, a capacitor C2, and a MOSFET Q3. One end of the Zener diode D3 is connected to the transistor Q2, and the other end of the Zener diode D3 is connected to the transistor Q1. The voltage divider resistor R7 is connected to the transistor Q2. The voltage divider resistor R7, the voltage divider resistor R8, and the capacitor C2 are connected in series. The MOSFET Q3 is connected to the monitoring power supply Vcc and the capacitor C2.

6. The undervoltage protection system for a driver chip as described in claim 1, characterized in that, The output drive circuit is used for undervoltage signal output, and the control circuit supplies voltage V2.

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