Patent ID: 6864724
Filing Date: 2005-03-08
Classification: H03F,H03G

Abstract:
1. A current to voltage conversion circuit employing a gain switching circuit, comprising: a photoelectric conversion device for receiving an optical signal and generating current corresponding thereto; current source current mirror means connected between a drive voltage and said photoelectric conversion device for supplying the same amount of current as that of the current generated by said photoelectric conversion device; an amplifier for receiving a current signal and outputting a voltage signal corresponding thereto; read current mirror means for transferring the current from said current source current mirror means to an input terminal of said amplifier in response to a switching control signal; write current mirror means for transferring said current from said current source current mirror means to said input terminal of said amplifier in response to said switching control signal; switching means for selectively turning on said read current mirror means and said write current mirror means in response to said switching control signal; and a feedback resistor connected between said input terminal of said amplifier and an output terminal of said amplifier.