Fast digital isolator

Abstract

The invention relates to a digital isolator comprising a logic module () for receiving an input signal D, and providing command signals () to sawtooth modulators. A first sawtooth modulator provides a first sawtooth signal at a node Acomprising a fast rising edge triggered by a rising edge of a control signal, followed by a slow falling edge, when D equals 1 and comprises a fast falling edge triggered by a rising edge of a control signal, followed by a slow rising edge, when D equals 0. A second sawtooth modulator provides a second sawtooth signal at node A, inverted with respect to first sawtooth signal. Isolation capacitors () are connected to nodes Aand Aand are used as isolation barrier and as part of a high-pass filter together with dipoles Zand Z. Threshold comparators () provide the output signals Sand R. Based on these S and R output signals, the input signal D referred to ground Gcan be regenerated versus a ground Gusing for example SR logic gate, low pass filters or peak detectors.