Low-noise photodiode-amplifier circuit

A photodiode-amplifier circuit with the photodiode in the feedback path is presented. It is named the PIF-circuit. No resistor is needed at the amplifier input to provide a path to ground for the signal and leakage currents from the photodiode and the amplifier input bias current. Therefore, one potentially dominating noise source is eliminated. At frequencies below 10 kHz, the implemented PIF-circuit has an NEP/spl ap/3 fW//spl radic/Hz.<
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