Patent ID: 8822900

Claim:
A photodetector, comprising: a photodiode; a bias terminal operable to receive an excess bias voltage and to set a bias voltage across the photodiode; reset circuitry operable to control the bias voltage; and output circuitry operable to read a voltage that depends on photons incident on the photodiode, wherein the photodetector is operable in a first mode as an integrating sensor with the bias voltage being set below the breakdown voltage of the photodiode and with the output circuitry operable to read an analog integration output voltage from the photodiode; and wherein the photodetector is operable in a second mode as a single photon avalanche detector with the bias voltage being set above the breakdown voltage of the photodiode and with the output circuitry operable to read an analog avalanche output voltage responsive to timing of avalanches of the photodiode; and a current source coupled between the photodiode and a capacitor; wherein, in the second mode, the analog avalanche output voltage is read from the capacitor.