| 摘要 |
A capacitive feedback transimpedance amplifier 10 comprises a differential amplifier constructed of GaAs transistor Q1 and Q2 and has an input coupled to the output of an infrared detector 12 and an output expressive of the detector signal integrated over a predetermined interval of time. The amplifier has a transistor Q0 coupled to the input for coupling the input periodically to a predetermined voltage potential and a transistor Q9 coupled to the output of the amplifier for simultaneously periodically coupling the output to a predetermined voltage reference, thereby initializing the amplifier at the beginning of an integration period. A load is coupled between an amplifier output terminal a source of amplifier power. The load includes a resistor having a first terminal coupled to the amplifier output terminal and a second terminal coupled to a first GaAs load transistor. The first load transistor is serially coupled to a second load transistor. A gate terminal of each of the first and the second load transistors is coupled to the amplifier output terminal.
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