Patent ID: 9577753
Date: 2017-02-21
CPC Classifications: H03F,H04B

Claim:
1. A transimpedance amplifier for converting an input current to an output voltage, comprising: a first amplifier configured to convert a current signal to a voltage signal; a single-to-differential converter configured to convert the voltage signal to a differential voltage signal that is output as the output voltage; a feedback circuit configured to generate a control signal from the differential voltage signal; a bypass circuit configured to generate the current signal by subtracting a bypass current from the input current so that an average value of the current signal is maintained at a predetermined value; a monitor circuit configured to generate a monitor current from the control signal, the monitor current being proportional to the bypass current; and an offset circuit configured to provide a reference voltage so that the bypass current is maintained at a constant value when the input current is null, wherein the single-to-differential converter includes a differential amplifier having a positive phase input and a negative phase input, the positive phase input receiving one of the voltage signal and the reference voltage, the negative phase input receiving the other of the voltage signal and the reference voltage, the differential amplifier generating the differential voltage signal by amplifying a voltage difference between the positive phase input and the negative phase input.