Compact and rapid detection quenching circuit for SPAD arrays

An innovative active-quenching circuit for single photon avalanche diode is presented. A differential amplification circuit based on offset control scheme is adopted to realize rapid avalanche signal discrimination. In order to save the die area, a voltage-controlled transistor acting as a sensing resistance is used. Compared with other traditional circuits, the proposed circuit does not need reference voltage and can realize low threshold voltage comparison. Therefore, it preserves the advantages of compact area and rapid detection, which can be applied in array situation.