| 摘要 |
PROBLEM TO BE SOLVED: To provide a transimpedance amplifier on which downsizing is implemented while appropriately adjusting a response time.SOLUTION: A TIA1 includes a TIA core section 11, a differential amplifier 12, a bypass circuit 13 which extracts a part of current, and a feedback control circuit 14 which controls the amount of the current to be extracted. The feedback control circuit 14 includes: a filter circuit 18 by which a low-frequency component of an output signal is filtered out; a current switched voltage shift circuit 19 which includes a voltage controlled current source IS1 and to which an output signal of the filter circuit 18 is inputted; a current switched voltage shift circuit 20 which includes a voltage controlled current source IS2 and to which a first threshold voltage is inputted; a voltage comparator 21 which outputs a control signal for controlling the bypass circuit on the basis of output signals from the current switched shift circuits 19 and 20; and a hysteresis voltage comparator 22 for controlling the voltage controlled current sources IS1 and IS2 on the basis of the control signal and a second threshold voltage. |
