Self-quenching, Forward-bias-reset for Single Photon Avalanche Detectors in 1.8V, 0.18µm process

We present a fully integrated, Single Photon Avalanche Detector (SPAD) using only standard low-voltage (1.8V) CMOS devices in a 0.18 μm process. The system requires one high-voltage AC signal which alternately reverse biases the SPADs into avalanche breakdown and then resets with a forward bias. The proposed self-quenching circuit intrinsically suppresses after-pulse effects, improving signal to noise ratio while still permitting fine time resolution. The required high- voltage AC signal can be generated by resonant structures and can be shared across arrays of SPADs.