provided is a current - voltage conversion amplifier circuit including : a plurality of light receiving devices generating a current signal proportional to an amount of light by receiving the light ; multipliers amplifying the current signal , converting the amplified current signal into a first voltage signal , outputting the amplified current signal , or outputting the converted first voltage signal ; multi input amplifiers outputting first and second output voltage pairs through a process for receiving output values of multipliers and an offset voltage and amplifying the received output values and offset voltage ; a multiplexing unit selecting and outputting one first and second output voltage pair among the first and second output voltage pairs outputted from multi input amplifiers ; and a signal conversion unit converting a difference value between first and second output voltages outputted from the multiplexing unit and outputting the converted digital signal .