Offset voltage compensation circuit and isolation amplifier device including the same

An isolation amplifier device, comprising:

• a transmitting circuit configured to convert a differential input voltage to a modulated pulse signal;
• an isolation coupler configured to be driven by the modulated pulse signal and generate an isolation signal;
• and
• a receiving circuit configured to receive, demodulate, and amplify the isolation signal, so as to generate a differential output voltage,
• wherein the receiving circuit includes an output stage for amplifying the isolation signal, and the output stage has an offset voltage compensation circuit, which includes:
• a first amplifier having a first input connected to a first differential input node and a first output connected to a first differential output node;
• a second amplifier having a first input connected to a second differential input node and a second output connected to a second differential output node;
• a first current source connected to a second input of the first amplifier for providing a first current;
• a second current source connected to a second input of the second amplifier and configured to provide a second current;
• a first resistor connected between the second input of the first amplifier and the first output;
• and
• a second resistor connected between the second input of the second amplifier and the second output;
• wherein the first current source is controlled according to the second current and a difference between a first initial output voltage and a second initial output voltage, such that an offset voltage between the first output and the second output is compensated.