US Patent 9531376 Solid state relay using capacitive isolation

An oscillator supplies a clock signal having a frequency determined in part according to a received current. A transmit side charge pump is coupled to the clock signal and boosts a voltage supplied to the charge pump to generate a boosted voltage. A driver circuit drives a transmit signal having a frequency based on the clock signal and a voltage based on the boosted voltage to a capacitive isolation communication path. A receive side charge pump is coupled to the isolation capacitors of the isolation communication path and boosts a voltage of the received signal on the receive side of the isolation communication path and supplies a gate signal with the boosted voltage to a gate of at least one transistor.