Patent ID: 7755433

Claim:
A preamplifier, comprising: a single-ended amplifier which converts an input current signal into a voltage signal, and outputs an amplified voltage signal according to a preset amplification gain; a differential amplifier which includes first and second differential inputs, and which outputs a negative-phase signal and a positive-phase signal, wherein the amplified voltage signal is applied to the first differential input of the differential amplifier; an operational amplifier which includes first and second inputs which respectively receive the negative-phase signal and the positive-phase signal, wherein an output of the operational amplifier is applied to the second differential input of the differential amplifier; and a clipping circuit that clips an amplitude of the negative-phase signal output by the differential amplifier, wherein the clipping circuit includes a diode connected between positive power terminal and a signal line transmitting the negative-phase signal, wherein an anode of the diode is connected to the positive power terminal.