US Patent 11601203 Transimpedance amplifier for receiving burst optical signal

A transimpedance amplifier includes a feedback circuit that generates a bypass current in accordance with a charging voltage of a capacitor based on a difference between a voltage signal and a reference voltage signal, a differential amplifier circuit that generates a differential signal in accordance with the difference between the voltage signal and the reference voltage signal, and a detector circuit that resets the charging voltage of the capacitor in response to a detection of end of a burst optical signal. The feedback circuit detects start of the burst optical signal based on the charging voltage, maintains a time constant at a first time constant for a predetermined period from the detection of the start of the burst optical signal, and, upon an elapse of the predetermined period, switches the time constant from the first time constant to a second time constant larger than the first time constant.