A photodetector includes a photodiode and output circuitry coupled to the photodiode. The photodetector is configurable for operation in at least two modes. A first configurable mode operates the photodetector as an integrating sensor. In this first mode, a bias voltage across the photodiode is set below the breakdown voltage of the photodiode and the output circuitry is configured to read an analog integration output voltage from the photodiode. A second configurable mode operates the photodetector as a single photon avalanche detector. In this second mode, the bias voltage across the photodiode is set above the breakdown voltage of the photodiode and the output circuitry is configured to read an avalanche output voltage.