Patent ID: 9671284
Date: 2017-06-06
CPC Classifications: G01J,H01L,H03H,H03K

Claim:
1. A circuit, comprising: a single-photon avalanche diode for providing an event signal in response to an avalanche event occurring in the single-photon avalanche diode; a threshold discriminator connected to the single-photon avalanche diode and configured to provide a first signal indicative of the event signal; a quenching circuit configured to assert a second signal, based on a leading edge of the first signal, the second signal driving a quenching transistor connected to the single-photon avalanche diode; a delay element configured to output a third signal being a delayed version of the first signal, the delay element including a first regulator and a second regulator, the delay element being programmable, based on a selection signal, to enable one of the first regulator and the second regulator and to disable the other one of the first regulator and the second regulator; and a reset circuit configured to assert a fourth signal, based on an edge of the third signal, the fourth signal driving a reset transistor connected to the single-photon avalanche diode; wherein the delay element is configurable in one of two distinct delay resolution regimes, each delay resolution regime corresponding to only one edge of the first signal being actively delayed by the delay element when one of the first regulator and the second regulator is enabled and the other one of the first regulator and the second regulator is turned off.