CMOS image sensor with current mirror
US7750281B2 · kind B2 · utility
9Cited by
5References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 13, 2009 |
| Grant date | Jul 6, 2010 |
| Priority date | — |
| Expiry date | Jan 13, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/1865
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image sensor includes a pixel with a drive transistor and a select transistor. The drive transistor is driven according to a voltage at a floating diffusion node. The select transistor is coupled in series with the drive transistor for being turned on when the pixel is selected. The image sensor also includes a current mirror unit having first and second branches conducting mirrored currents. The first branch is coupled to the drive transistor, and the second branch is coupled to the select transistor at an output node of the pixel. With such biasing by the current mirror, gain drop in the drive transistor is minimized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.