Pre-charging a wide analog bus for CMOS image sensors
US6818877B2 · kind B2 · utility
2Cited by
6References
7Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 17, 2002 |
| Grant date | Nov 16, 2004 |
| Priority date | — |
| Expiry date | Aug 16, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/60
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A video bus for an array of pixel amplifiers is designed for a minimum quiescent current draw. The pixel amplifiers (or column amplifiers) are designed with high impedance pull-ups and low impedance pull-downs to conserve over-all power dissipation. The video bus is provided with a high-impedance P-FET to reset the bus to drain voltage VDD for a very short time between the time one pixel (or column) is selected the time the next is selected, so that the video bus only has to be discharged through the low impedance N-FET. The bus does not have to be current-sourced by the P-FET.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.