Protection circuit for preventing overvoltage of chip pins in standby process and after startup

Abstract

The invention relates to the technical field of chip protection circuits, in particular to a protection circuit for preventing overvoltage of chip pins in a standby process and after startup, which comprises a connector interface circuit module, a chip, constant power supplies VCC1 and VCC2, a non-constant power supply VCC3, an NMOS transistor Q1, a triode Q2, diodes D1 and D2 and a voltage stabilizing diode D5. According to the invention, the problems that when a product is in a standby state, the chip has no power supply, if the voltage input by the interface circuit is too high, the voltageis input to the pin of the chip to cause abnormal internal work of the chip, and the chip is damaged due to the fact that the voltage stabilizing diode is generally arranged for clamping voltage protection in the existing chip directly connected with the connector interface circuit are solved. And the problem of abnormal awakening or other faults of the product due to the fact that the input highvoltage is input into the related output pins of the chip and the related output pins output high-level signals can be solved.

Description

technical field [0001] The invention relates to the technical field of chip protection circuits, in particular to a protection circuit for preventing chip pins from overvoltage during standby and after starting up. Background technique [0002] In the existing chip circuit, for the chip directly connected to the interface circuit of the connector, in order to prevent the chip pin from being damaged due to the high input circuit of the interface circuit, a Zener diode is usually added at the input end of the chip pin for voltage clamping protection. However, using this method will cause the chip to have no power supply when the product is in standby mode. If the input voltage of the interface circuit is too high, the voltage will still be a relatively high voltage after being regulated by the Zener diode. This voltage is input to the chip lead. pin, and because the chip has no power supply, it will cause the internal operation of the chip to be abnormal, and it may also cause...

AI Technical Summary

Problems solved by technology

[0004] The content of the present invention is to provide a protection circuit for preventing overvoltage of the chip pins during the standby process and after starting up, which mainly solves the problem of the existing and connector interface circuit Directly connected chips are usually equipped with Zener diodes for voltage clamping protection. As a result, when the product is in standby mode, the chip has no power supply. If the input voltage of the interface circuit is too high, the voltage input to the chip pin will cause the chip to Abnormal internal work may also lead to high input voltage entering the relevant output pins of the chip, causing the relevant output pins to output high-level signals, causing abnormal wake-up of the product or other failures

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