Abstract:Avalanche photodiodes have high output and high stability requirements for bias power in Geiger mode. This paper designs an avalanche photodiode (APD) with high boost ratio, high precision, low temperature drift, small size, and low power. Bias power supply, this module uses switching chip IC and flyback transformer to achieve high step-up ratio, realizes precise output control through precision op amp and T-type resistor feedback network, and designs appropriate compensation network to improve system stability. The size of the module is 2.5?2.5cm, the output voltage is adjustable from 0 to 450V, and the maximum ripple does not exceed 5.4mV. By changing the control voltage, any type of APD in Geiger mode can be biased, and the maximum deviation of the bias voltage does not exceed 0.5%.