Electrostatic protection method and circuit having detection control circuit

Abstract

The present invention discloses an electrostatic protection method with detection control circuit and circuit which belongs to electrostatic protection field, and the method comprises the following steps: detect input voltage on input / output terminal of a chip internal circuit through a detection circuit, when input voltage smaller than trigger voltage set by the detection circuit, it is judged to be working voltage, and working current corresponding to the working voltage flows into the chip internal circuit through input / out terminal of the chip internal circuit directly, and the trigger voltage is smaller than minimum breakdown voltage of the chip internal circuit; when input voltage on input / output terminal of a chip internal circuit is detected bigger than or equal to the trigger voltage, it is judged to be electrostatic discharge voltage, and the detection circuit controls electrostatic discharge current corresponding to the electrostatic discharge voltage bleed through a bleeder circuit, thereby the input voltage is clamped in safe voltage range and plays the role of internal circuit protection. The present invention realizes clamp or normal work through detecting input voltage and control bleed.

Description

technical field [0001] The invention belongs to the field of electrostatic protection of integrated circuits, and in particular relates to an electrostatic protection method with a detection control circuit and a circuit for realizing the method. Background technique [0002] In chip applications, electrostatic discharge will cause most chips to be destroyed, but static electricity is everywhere. Static electricity will accumulate on the human body and machines during the production, assembly, and testing of chips. When objects touch each other, a current loop is formed, causing destruction inside the chip. The static electricity on the human body will form a discharge circuit through the pins of the chip. The discharge process will generate an instantaneous discharge current of several amperes in a short time of several hundred nanoseconds (ns). For general consumer chips, the instantaneous discharge The peak of the current can reach 1.3 amperes to dozens of amperes, and t...

AI Technical Summary

Problems solved by technology

However, the problem still existing in the SCR protection circuit 30 is that the trigger voltage of the SCR protection circuit 30 is difficult to control, and at the same time, it is necessary to prevent the latch-up effect (latchup) of the circuit device.

Although the trigger voltage of the SCR protection circuit 30 can be increased by adding a guard ring or adopting a larger layout interval, the high trigger voltage will not be able to conduct in real time to discharge the instantaneous large current when the electrostatic discharge occurs, which will cause the protected device to be damaged. first destroyed by electrostatic discharge

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