Design and implementation of FPGA bias-temperature compensation circuit used in APD

APD offers advantages such as high gain and rapid response speed, but it is temperature-sensitive. To ensure gain stability of APD, we design an FPGA bias-temperature compensation circuit which includes an APD detector module, a temperature detection module, a high-voltage module, and an FPGA processing control module. The temperature detection module detects the temperature of APD and transmits it to the FPGA via ADC. After processing by the FPGA, a control signal is obtained and is transmitted to the high-voltage module via DAC, thereby enabling adaptive regulation of the bias voltage. Test results demonstrate that when the operating temperature varies, the FPGA bias-temperature compensation circuit effectively stabilizes the output voltage of APD, confirming its temperature compensation capability. This work thus provides a technical foundation for more practical exploration of APD devices.