Phase reversal and electrostatic reinforcement protection circuit

Abstract

The invention discloses a phase reversal and electrostatic reinforcement protection circuit. The phase reversal and electrostatic reinforcement protection circuit comprises a resistor Rinx, a resistor Riny, a resistor Rin', a diode D1, a diode D2, a diode D3, a parasitic resistor Rj1 and a parasitic resistor Rj2, wherein one end of the resistor Riny is connected with a positive input port INP of the operational amplifier, the other end of the resistor Riny is connected with one end of the resistor Rinx and one end of the parasitic resistor Rj1, the other end of the parasitic resistor Rj1 is connected with one end of the diode D1, and the other end of the diode D1 is connected to a negative power supply; the other end of the resistor Rinx is connected with one end of the resistor Rin' and one end of a parasitic resistor Rj2, the other end of the parasitic resistor Rj2 is connected with one end of a diode D2, and the other end of the diode D2 is connected to a negative power supply; the other end of the resistor Rin' is respectively connected with one end of a diode D3 and an input geminate transistor base electrode in the operational amplifier, and the other end of the diode D3 is connected with a positive power supply. The phase reversal and electrostatic reinforcement protection circuit has a static strengthening function and a phase overturning protection function at the same time.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, in particular to a phase reversal and electrostatic reinforcement protection circuit. Background technique [0002] The phase reversal protection circuit of the input port is one of the important measures to improve the reliability of the device. In particular, for the bipolar rail-to-rail op amp, its wide operating voltage range up to the power rail makes it very likely that the input signal will exceed the power rail in some extreme engineering applications, resulting in output signal errors and accompanying overcurrent phenomena. Resulting in device parameter drift or even failure. In addition, the anti-static technology of the port is also a key means to improve the reliability of the device. Since the application environments of op amps vary greatly, among which failures due to ESD account for a large proportion, designing a suitable electrostatic hardening circuit is an import...

AI Technical Summary

Problems solved by technology

[0003] However, the current mainstream anti-phase reversal protection structure has no anti-static ability, and the traditional anti-static structure of the port cannot meet the anti-phase reversal requirements of the input terminal. Among the operational amplifiers

Most rail-to-rail operational amplifiers on the market require the input voltage to be several volts higher than the positive power supply voltage or lower than the negative power supply voltage. However, the traditional antistatic structure locks the voltage drop between the input terminal and the positive and negative power supplies at the conduction of the diode. The voltage drop of the on-voltage cannot meet the application requirements

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