Silicon Laboratories Inc.
Receiver architecture for digital isolators employing notch filters common mode transient immunity

Abstract:

A technique for attenuating common mode transient events uses a differential receiver circuit including a band-stop filter having a stopband f.sub.SB around a notch frequency f.sub.n of a received signal. The differential receiver circuit includes a first high-pass filter coupled in series with the band-stop filter. The notch frequency f.sub.n is less than a carrier frequency f.sub.c of a signal received by the differential receiver circuit. The band-stop filter may include a buffer circuit and a notch filter coupled in series with the buffer circuit. The notch filter may have a second stopband around the notch frequency f.sub.n. The differential receiver circuit may have a propagation delay that is independent of a pulse width of common mode transient energy attenuated by the differential receiver circuit.