Patent ID: 8901475

Claim:
An avalanche photodiode (APD) biasing system, comprising: a current mirror having an input node and an output node; an avalanche photodiode (APD) coupled to the output node of the current mirror; a voltage-to-current converter coupled to the input node of the current mirror, the voltage-to-current converter configured to transmit current through the current mirror to the APD; and a feedback path coupled between the output node of the current mirror and the voltage-to-current converter, the feedback path configured to sense a voltage across the APD and provide, based on the sensed voltage, an input signal to the voltage-to-current converter for controlling the current transmitted by the voltage-to-current converter, wherein the feedback path is arranged to limit a voltage of the input signal such that the current transmitted by the voltage-to-current converter is limited thereby preventing damage to the APD.