Anode sensing circuit for single photon avalanche diodes
US11349042B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 2019 |
| Grant date | May 31, 2022 |
| Priority date | — |
| Expiry date | May 1, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/8037
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A pixel includes a single photon avalanche diode (SPAD) having a cathode coupled to a high voltage supply through a quenching element, with the SPAD having a capacitance at its anode formed from a deep trench isolation, with the quenching element having a sufficiently high resistance such that the capacitance is not fully charged when the SPAD is struck by an incoming photon. The pixel includes a clamp transistor configured to be controlled by a voltage clamp control signal to clamp voltage at an anode of the SPAD when the SPAD is struck by an incoming photon to be no more than a threshold clamped anode voltage, and readout circuitry coupled to receive the clamped anode voltage from the clamp transistor and to generate a pixel output therefrom. The threshold clamped anode voltage is below a maximum operating voltage rating of transistors forming the readout circuitry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.