To provide a transimpedance amplifier capable of reducing a harmful effect such as parasitic capacitance or the like without using a feedback resistor to be thereby able to restrain the distortion of an output voltage converted from an input current when the input current is a high-speed signal.
The transimpedance amplifier is equipped with a MOS transistor Q1 whose gate is grounded via a capacitor CG1 for an alternate current and a MOS transistor Q2 that is subjected to cascode connection with the MOS transistor Q1, whose gate is grounded via a capacitor CG2 for the alternate current, and further whose drain is connected to a load resistor RL. The input current Iin is supplied to a common junction of the MOS transistors Q1 and Q2, so that the output voltage depending on the input current Iin is obtained from the load resistor RL.
Fujitsuna Hideyoshi
Osamu Suzawa