A 3.3-to-25V all-digital charge pump based system with temperature and load compensation for avalanche photodiode cameras with fixed sensitivity

ABSTRACT This paper presents a digitally controlled charge pump (DCP) to supply high voltages, while ensuring temperature and load current independence of excess bias in cameras based on avalanche photodiodes. This is achieved through a single-photon avalanche diode (SPAD) based monitoring mechanism that continuously reconfigures the DCP using a feedback loop to compensate breakdown voltage variations by temperature and load current in real time. The sensitivity of the SPADs, or photon detection probability (PDP), is maintained to within 1.9% when the temperature shifts from 28°C to 65°C and the load current changes from 0 μA to 100 μA.