Overvoltage protection circuit and IC (integrated circuit)

Abstract

The invention discloses an overvoltage protection circuit, comprising a voltage judgment module, an overvoltage protection module and a switching element, wherein the switching element is connected between an input voltage and the ground; the voltage judgment module samples the input voltage and outputs high-low level signals; and the overvoltage protection module switches on the switching element when the voltage judgment module outputs the high level signals and switches off the switching element when voltage judgment module outputs the low level signals. In addition, the invention also discloses an IC (integrated circuit) using the overvoltage protection circuit. The overvoltage protection circuit and the IC can distribute currents by an external resistor which is connected between a power supply and a voltage input end, thus reducing input voltage and protecting a working circuit effectively. Meanwhile, the overvoltage circuit is connected with the external resistor, thus the heat which is generated at the time of overvoltage can be centralized on the external resistor, thereby being convenient for radiating.

Description

【Technical field】 [0001] The invention relates to a control circuit, in particular to an overvoltage protection circuit and an integrated circuit. 【Background technique】 [0002] In the application of integrated circuits, there will often be a problem that the input voltage fluctuates too much, especially when the voltage exceeds a preset value, which may easily cause damage to the device. Therefore, in the circuit, the input voltage is generally sampled regularly, and it is judged whether the current voltage is too high, and if it is too high, measures are taken to reduce the voltage to protect the working circuit. [0003] The general method is to use a Zener tube to stabilize the voltage input to the chip. However, when the working circuit uses a small current, the Zener tube will share a large current, so the heat generation is very large, which poses a challenge to the heat dissipation of the chip. higher requirements. 【Content of invention】 [0004] Based on this, ...

AI Technical Summary

Problems solved by technology

[0003] The general method is to use a Zener tube to stabilize the voltage input to the chip. However, when the working circuit uses a small current, the Zener tube will share a large current, so the heat generation is very large, which poses a challenge to the heat dissipation of the chip. higher requirements

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