Extended hold-off time for SPAD quench assistance
US11105679B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 2019 |
| Grant date | Aug 31, 2021 |
| Priority date | — |
| Expiry date | Dec 12, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2001/4466
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A photodetection circuit includes a single photon avalanche diode (SPAD), and an active quenching circuit coupling the SPAD to an intermediate node and having a variable RC constant. The variable RC constant provides a first RC constant during an idle state so that when the SPAD detects a photon, the SPAD avalanches to begin quenching to set a magnitude of a voltage at a terminal of the SPAD to a quench voltage, the quench voltage being greater than a threshold voltage; a second RC constant greater than the first RC constant during a hold off period during which the quenching occurs so as to maintain the voltage at the terminal of the SPAD at a magnitude that is above the threshold voltage during the hold off period; and a third RC constant less than the second RC constant but greater than the first RC constant during a recharge period during which the SPAD is recharged.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.