Common-mode transient interference suppression circuit and isolator

Abstract

The invention discloses a common-mode transient interference suppression circuit and an isolator. The common-mode transient interference suppression circuit comprises a first-stage high-pass filter, a second-stage high-pass filter, a signal demodulation circuit and a common-mode detection circuit, wherein the first-stage high-pass filter, the second-stage high-pass filter and the signal demodulation circuit are connected in series; the common-mode detection circuit is arranged between the first-stage high-pass filter and the second-stage high-pass filter; the first-stage high-pass filter and the second-stage high-pass filter are used for sequentially filtering the input signal of the signal receiving end, outputting a differential signal and providing a current discharge channel when common-mode transient interference occurs; the common-mode detection circuit is used for detecting the differential signal, generating a common-mode transient detection result signal and outputting the common-mode transient detection result signal to the signal demodulation circuit; and the signal demodulation circuit is used for demodulating the differential signal according to the common-mode transient detection result signal to obtain an original signal. According to the scheme, signal decoding abnormity caused by common-mode transient interference can be effectively suppressed, and the common-mode transient interference resistance of the isolator is improved.

Description

technical field [0001] The invention relates to the technical field of circuits, in particular to a common mode transient interference suppression circuit, and also to an isolator. Background technique [0002] The isolator is an intermediate circuit between the signal output end and the signal receiving end. It is often used to deal with the problem that the two sides of the isolator do not share the same ground, so that the circuits in different voltage domains can maintain communication, and at the same time prevent the circuits in different voltage domains from interacting with each other. interference. When the reference ground on one side of the isolator is jittered, common mode transient interference will occur, which may affect the accuracy of the transmission signal of the isolation channel. [0003] The traditional isolator solution to deal with common mode transient interference is to use differential structure and ON-OFF Keying (OOK) coding method. The schematic...

AI Technical Summary

Problems solved by technology

When common-mode interference occurs between the TGND of the signal transmitting end and the RGND of the signal receiving end, the capacitors C1, C2, and the resistors R1, R2, R3, and R4 can reduce the common-mode interference, but due to the common-mode interference of ...

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