Patent ID: 7715726

Claim:
An optically isolated circuit device, comprising: a divider circuit for receiving an input clock signal having an input clock frequency and dividing the input clock signal down to produce a first clock signal having a first clock frequency; a first opto-isolator circuit; a first driver circuit for receiving the first clock signal and driving an input of the first opto-isolator circuit at the first clock frequency; a first receiver circuit for receiving an output of the first opto-isolator circuit at the first clock frequency; a phase-locked loop circuit for receiving an output of the first receiver circuit and synthesizing a second clock signal having a second clock frequency that is a multiple of the first clock frequency, wherein the second clock frequency is equal to the input clock frequency; a clocked circuit for producing an output in response to the second clock signal; a second opto-isolator circuit; a second driver circuit for receiving the output of the clocked circuit and driving an input of the second opto-isolator circuit at the second clock frequency; and a second receiver circuit for receiving an output of the second opto-isolator circuit and producing a digital output signal.