A 6.6V Switch for SPAD Gating up to 1000MHz in 0.35μm BiCMOS Technology

Abstract

Integration of a BiCMOS cascoded gater with a Single-Photon-Avalanche-Diode (SPAD) aimed at achieving a high gating frequency is proposed. The gater configuration utilizes an NPN transistor as a switch for the excess bias of the SPAD to minimize quenching time. With an excess bias voltage of 6.6V, the gater achieves successful operation up to IGHz. Furthermore, the measured fall time for quenching the SPAD, defined as the cathode potential drop from 90% to 10% of the excess bias, is 175ps. Fabrication of both the gater and SPAD was carried out using 3.3V/0.35um pure-silicon BiCMOS technology.