Temperature compensated APD detector bias and transimpedance amplifier circuitry for laser range finders

摘要

Laser range finder circuitry including an avalanche photodiode detector, a capacitor for storing a detector bias voltage, and a transimpedance amplifier for amplifying the detector signal. The capacitor is charged in response to a first control signal by a circuit employing first and second field effect transistors and is discharged in response to a second control signal by a circuit employing a third field effect transistor. An overload protection circuit including a single diode is provided to accommodate excessive charge created by backscatter upon initial laser firing. A temperature sensor is further provided to develop a temperature signal which may be monitored to adjust the detector bias voltage and other parameters so as to permit use of an associated laser range finder over a wide range of temperatures.