Design of Digital Circuit for Bias Voltage of Avalanche Photodiode

摘要

In order to ensure the APD's optimum operation in condition of different temperature, many bias voltage control schemes have been designed. Against the disadvantage of the conventional bias voltage control schemes and based on the multiplication mechanics, this paper analyzed the temperature how to have an effect on the avalanche gain, obtained the curves between bias voltage and temperature characteristic. Based on the false alarm control theory and the characteristic of the chip microcomputer's convenience to treating and holding digital information, a numeric control bias circuit auto-tracing the avalanche breakdown voltage is designed. This circuit can guarantee the normal work of APD in large variation of temperature, it is suitable for the photoelectric system of high-frequency and continuous signal detection.