Electronic circuit and electronic apparatus

An electronic circuit, comprising:

• a first circuit;
• a second circuit electrically insulated from the first circuit;
• and
• a transmitter configured to transmit signals between the first circuit and the second circuit, wherein
• the first circuit includes:
• an input terminal receiving an analog input signal;
• a first reference signal generator generating an analog first reference signal;
• and
• a first frequency converter converting a frequency of the analog input signal and a frequency of the analog first reference signal,
• the transmitter transmits the frequency-converted input signal and the frequency-converted first reference signal from the first circuit to the second circuit, and
• the second circuit includes:
• a second frequency converter converting the frequency of the transmitted input signal and the frequency of the transmitted first reference signal to obtain a restored input signal and a restored first reference signal;
• a second reference signal generator generating an analog second reference signal;
• a gain calculator calculating a gain to be adjusted of the restored input signal based on the restored first reference signal and the analog second reference signal;
• a gain adjustment device adjusting the gain of the restored input signal based on the calculated gain;
• and
• an output terminal outputting the gain-adjusted input signal.