Overvoltage protection circuit with temperature compensation

Abstract

The embodiment of the utility model discloses an overvoltage protection circuit with temperature compensation, which comprises an input module, a control module and an output module, and is characterized in that the input module is connected with the control module, and the control module is connected with the output module; the input module is used for sensing a voltage level and adjusting a signal; the control module controls the on-off state of the MOSFET according to the adjusted signal so as to realize overvoltage protection; and the output module is used for feeding back the change condition of the protection state. By implementing the circuit provided by the embodiment of the invention, different temperature characteristics of devices can be fully utilized, so that the whole system adapts to different environments to achieve a stable protection effect.

Description

Technical Field

[0001] This invention relates to the field of electronic device technology, and in particular to an overvoltage protection circuit with temperature compensation. Background Technology

[0002] Electronic devices, especially components made of semiconductor materials such as diodes, transistors, and integrated circuits, are highly sensitive to temperature in their operating environment. As temperature changes, the physical parameters of these devices (such as threshold voltage, on-resistance, and switching speed) also change. For MOSFETs, the effect of temperature is particularly significant. When the temperature rises, the threshold voltage of a MOSFET typically decreases, meaning that at the same gate voltage, the MOSFET is more likely to enter the conduction state. At high temperatures, the on-resistance of the MOSFET may increase, leading to more power loss and generating additional heat, creating a vicious cycle. Furthermore, prolonged exposure to high temperatures accelerates device aging, potentially causing problems such as increased leakage current and decreased breakdown voltage, severely impacting system stability and lifespan.

[0003] Many electronic devices are designed with only room temperature performance in mind. However, in actual use, changes in ambient temperature or self-heating can cause the operating conditions of these devices to deviate from the design expectations. Extreme temperature conditions are a common challenge, especially in industrial control, automotive electronics, and aerospace. In high-temperature environments, some devices may fail to start or operate unstablely. Prolonged exposure to high temperatures can shorten device lifespan, increase failure rates, and cause system parameter drift, affecting measurement accuracy and control system response.

[0004] Therefore, it is necessary to design a new circuit that can make full use of the different temperature characteristics of the devices, so that the whole system can adapt to different environments and achieve a stable protection effect. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an overvoltage protection circuit with temperature compensation.

[0006] To solve the above-mentioned technical problems, the objective of this invention is achieved through the following technical solution: providing an overvoltage protection circuit with temperature compensation, comprising: an input module, a control module, and an output module, wherein the input module is connected to the control module, and the control module is connected to the output module; the input module is used to sense the voltage level and adjust the signal; the control module controls the switching state of the MOSFET according to the adjusted signal to achieve overvoltage protection; and the output module is used to provide feedback on changes in the protection state.

[0007] The further technical solution is as follows: the input module includes voltage divider resistors R1 and R2; one end of voltage divider resistor R1 and one end of voltage divider resistor R2 are connected; the other end of voltage divider resistor R2 is connected to the control module.

[0008] The further technical solution is as follows: the control module includes a Zener diode D1 and a switching element; the Zener diode D1 is connected to the voltage divider resistor R2; the Zener diode D1 is connected to the switching element; and the switching element is connected to the output module.

[0009] The further technical solution is as follows: the switching device includes a MOSFET Q1, the gate of the MOSFET Q1 is connected to the Zener diode D1; the drain of the MOSFET Q1 is connected to the output module; and the source of the MOSFET Q1 is grounded.

[0010] The further technical solution is as follows: the control module also includes a resistor R3, one end of which is connected between the gate of the MOS transistor Q1 and the Zener diode D1, and the other end of which is grounded.

[0011] The further technical solution is as follows: the output module includes a load resistor R4, which is connected to the drain of the MOS transistor Q1.

[0012] The advantages of this invention compared to existing technologies are as follows: This invention fully utilizes the temperature characteristics of the device through precise design to ensure stable protection under different environmental conditions; the input module senses and adjusts the voltage signal to reduce the impact of temperature changes on the voltage sensing accuracy; the control module adjusts the switching state of the MOSFET according to the temperature compensation signal, thereby achieving temperature-stable overvoltage protection; the switching response of the MOSFET is adjusted according to the temperature characteristics to ensure timely activation of overvoltage protection at different temperatures; the output module feeds back the protection status changes to ensure that the circuit can operate stably and provide reliable protection according to changes in ambient temperature.

[0013] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 A schematic block diagram of an overvoltage protection circuit with temperature compensation provided for an embodiment of the present invention;

[0016] Figure 2 A detailed circuit diagram of an overvoltage protection circuit with temperature compensation provided for an embodiment of the present invention;

[0017] Explanation of the markings in the image:

[0018] 10. Input module; 20. Control module; 30. Output module. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0021] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0022] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0023] The performance of electronic devices is closely related to temperature, especially components made of semiconductor materials such as diodes, transistors, and MOSFETs. As temperature rises, the threshold voltage of a MOSFET decreases, and its on-resistance increases, leading to power loss and heat generation. Prolonged exposure to high temperatures accelerates device aging, increases leakage current, and reduces breakdown voltage, affecting system stability. Many devices are designed without considering temperature variations, which can lead to device failure and shortened lifespan, especially in high-temperature environments.

[0024] Therefore, this utility model embodiment provides an overvoltage protection circuit with temperature compensation, which makes full use of the different temperature characteristics of the devices, so that the whole system can adapt to different environments and achieve a stable protection effect.

[0025] Specifically, this overvoltage protection circuit employs a temperature compensation design, utilizing the temperature characteristics of the components to ensure stable system operation under varying environments. Input module 10 uses voltage divider resistors R1 and R2 to regulate the voltage signal, minimizing the impact of temperature changes on voltage sensing. In control module 20, Zener diode D1 stabilizes the voltage using its temperature characteristics, adjusting the gate of MOSFET Q1 and controlling the MOSFET's switching state. The coordinated operation of MOSFET Q1 and Zener diode D1 ensures reliable overvoltage protection activation at different temperatures. Output module 30 provides feedback on the protection status, ensuring the circuit responds to external environmental changes and maintains stable protection performance.

[0026] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0027] Please see Figure 1 The above-mentioned overvoltage protection circuit with temperature compensation includes: an input module 10, a control module 20, and an output module 30. The input module 10 is connected to the control module 20, and the control module 20 is connected to the output module 30. The input module 10 is used to sense the voltage level and adjust the signal. The control module 20 controls the switching state of the MOSFET according to the adjusted signal to realize overvoltage protection. The output module 30 is used to provide feedback on the changes in the protection state.

[0028] Specifically, input module 10 is responsible for real-time monitoring of the voltage level in the power supply line. It can not only detect the voltage magnitude but also adjust the signals entering the system according to set safety thresholds. If the detected voltage exceeds a predetermined safety range, input module 10 will modify the signal accordingly to prepare for subsequent processing. Furthermore, input module 10 may also include filters to reduce noise and unwanted interference.

[0029] The control module 20 receives the adjusted signal from the input module 10 and determines the switching state of the MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) accordingly. A MOSFET is a widely used semiconductor device in power management, and its operation is similar to that of an electronic switch. When the control module 20 detects an overvoltage condition, it triggers the MOSFET to disconnect, thereby cutting off the current path and protecting downstream devices from the effects of high voltage. Simultaneously, considering that changes in ambient temperature may affect the operating characteristics of the MOSFET, the control module 20 incorporates a temperature compensation mechanism to ensure accurate execution of the protection function under different temperature conditions.

[0030] Once an overvoltage event occurs and is processed by control module 20, output module 30 is responsible for reporting the current status to the user or other monitoring systems. This can be achieved by changing the color of indicator lights, sending digital signals, or transmitting information via a communication interface. The feedback provided by output module 30 is crucial for taking timely corrective measures, such as reminding the user to shut down affected equipment or automatically activating backup power.

[0031] In summary, this temperature-compensated overvoltage protection circuit design can effectively protect sensitive electronic equipment from voltage surges while ensuring stable and reliable operation even in environments with large temperature fluctuations.

[0032] In one embodiment, please refer to Figure 2 The input module 10 mentioned above includes voltage divider resistors R1 and R2; one end of voltage divider resistors R1 and R2 are connected; the other end of voltage divider resistor R2 is connected to control module 20. One end of these two resistors is connected together, and the other end is connected to the power supply VH and control module 20 respectively. Through the voltage divider effect of these two resistors, the input voltage VH can be adjusted to a suitable range for subsequent processing by control module 20.

[0033] In one embodiment, please refer to Figure 2 The control module 20 mentioned above includes a Zener diode D1 and a switching element. The Zener diode D1 is connected to the voltage divider resistor R2; the Zener diode D1 is connected to the switching element; and the switching element is connected to the output module 30.

[0034] In one embodiment, please refer to Figure 2 The aforementioned switching device includes a MOSFET Q1, the gate of which is connected to a Zener diode D1; the drain of the MOSFET Q1 is connected to the output module 30; and the source of the MOSFET Q1 is grounded.

[0035] In one embodiment, please refer to Figure 2 The control module 20 also includes a resistor R3. One end of resistor R3 is connected between the gate of MOSFET Q1 and Zener diode D1, and the other end of resistor R3 is grounded. The function of this resistor R3 is to ensure the stability of the gate voltage of MOSFET Q1.

[0036] In one embodiment, please refer to Figure 2 The aforementioned output module 30 includes a load resistor R4, which is connected to the drain of the MOSFET Q1. When the MOSFET Q1 is turned on, current flows through the load resistor R4, thereby changing the voltage level of the FB point. The change in the state of the FB point can be detected by a microcontroller or other receiver, and corresponding protection measures can be implemented.

[0037] In this embodiment, at room temperature: when the input voltage VH reaches the protection point, the voltage across Zener diode D1 reaches its regulated value through the voltage division effect of R1 and R2. Zener diode D1 turns on, causing the gate voltage of MOSFET Q1 to rise and reach the turn-on threshold VGSth.

[0038] When MOSFET Q1 is turned on, current flows through the load resistor R4, the voltage level at point FB becomes low, and the signal is transmitted to the microcontroller or other receiver, triggering protection measures.

[0039] At high temperatures: Due to the negative temperature effect of VGSth value of MOSFET devices, that is, the VGSth value decreases as the temperature rises. If the parameters of other devices remain unchanged at high temperatures in the circuit design, then due to the voltage division effect, the gate-source voltage of MOSFET Q1 will reach the turn-on threshold when the total voltage VH is still very low, and overvoltage protection will be triggered prematurely.

[0040] The ingenious aspect of this invention lies in utilizing the positive temperature characteristic of certain series of Zener diodes. As the temperature rises, the Zener voltage across the Zener diode increases, and the voltage drop between the gate and source of the MOSFET decreases. This allows the circuit to reach the overvoltage threshold at the same point as at room temperature, thus enabling protection. This ensures that the circuit provides the same overvoltage protection in different temperature environments without prematurely triggering protection at high temperatures, which would affect the normal operation of the system.

[0041] The circuit in this embodiment utilizes the temperature characteristics of the devices themselves for temperature complementarity, without adding any additional costs. It is simple to implement and highly economical.

[0042] In summary, this circuit, through reasonable voltage division and regulation design, achieves consistent overvoltage protection under different temperature environments, effectively avoiding premature protection issues caused by temperature changes.

[0043] The above-described overvoltage protection circuit with temperature compensation fully utilizes the temperature characteristics of the devices through precise design to ensure stable protection under different environmental conditions. The input module 10 senses the voltage signal and adjusts it to reduce the impact of temperature changes on the voltage sensing accuracy. The control module 20 adjusts the switching state of the MOSFET according to the temperature compensation signal, thereby achieving temperature-stable overvoltage protection. The switching response of the MOSFET is adjusted according to the temperature characteristics to ensure timely activation of overvoltage protection at different temperatures. The output module 30 provides feedback on the protection state changes to ensure that the circuit can operate stably and provide reliable protection according to changes in ambient temperature.

[0044] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An overvoltage protection circuit with temperature compensation, characterized in that include: The system includes an input module, a control module, and an output module. The input module is connected to the control module, and the control module is connected to the output module. The input module senses the voltage level and adjusts the signal. The control module controls the switching state of the MOSFET based on the adjusted signal to achieve overvoltage protection. The output module provides feedback on changes in the protection state. The input module includes voltage divider resistors R1 and R2; one end of voltage divider resistor R1 and one end of voltage divider resistor R2 are connected; the other end of voltage divider resistor R2 is connected to the control module; the control module includes a Zener diode D1 and a switch; the Zener diode D1 is connected to the voltage divider resistor R2; the Zener diode D1 is connected to the switch; the switch is connected to the output module; the switch includes a MOSFET Q1, the gate of which is connected to the Zener diode D1; the drain of the MOSFET Q1 is connected to the output module; the source of the MOSFET Q1 is grounded; the control module also includes a resistor R3, one end of which is connected between the gate of the MOSFET Q1 and the Zener diode D1, and the other end of which is grounded; the output module includes a load resistor R4, which is connected to the drain of the MOSFET Q1.

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