Abstract:
In this paper, a dual-rail charge pump bias circuit for avalanche photodiodes is presented. The proposed circuit was fabricated and measured on a printed circuit board (PCB). Experimental measurements show that it is capable of providing up to 50 V bias voltage and delivering more than 40 mW of power for shallow-junction planar APDs that operate between 25 V and 40 V, allowing avalanche currents in the mA range. The circuit requires only a dual supply rail at ± 5 V which makes it useful for reducing the system complexity and the cost of using additional external power supplies in an APD-based sensing system. With the shunt regulators in the circuit, the bias voltage can be accurately controlled and easily adjusted.
