Selecting Single Photon Avalanche Diode (SPAD) Passive-Quenching Resistance: An Approach

An approach useful for designing the passive quenching circuitry of single-photon avalanche diodes (SPADs) is presented. A method is introduced which enables a chip designer to correctly select the appropriate resistance of the passive quenching component of the chip. The range of external resistance required for adequate quenching can be determined solely from the measured dc I-V characteristics of the SPAD. The tradeoff between various allowable values of resistance is discussed.