Floating clock sensor for buffered, independent, non-destructive readout of charge transfer devices
US4041298A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 24, 1975 |
| Grant date | Aug 9, 1977 |
| Priority date | — |
| Expiry date | Oct 24, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/891
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
In a charge transfer device (CTD), such as a charge coupled device (CCD), a gate electrode employed for sensing of the charge packet being transferred, or coupled through the device is clocked during one phase of the four-phase clocking and is permitted to float, i.e., be isolated, during a sensing phase of the four-phase clocking. Since the sensor is a gate electrode rather than a diffusion, it presents no obstruction to the propagation of charge down the channel. Since sensing occurs while the electrode is floating, the sensing or readout function does not have any detrimental effect on the propagation of charge down the channel, i.e., it affords a truly non-destructive readout. During a clocking phase in which charge is isolated under a different gate electrode, an attractive voltage clock pulse is applied to the sensor electrode, rendering it attractive. The sensor electrode is then isolated from the clocking source and, in the appropriate succeeding clocking intervals, the charge advances to the well under the sensor electrode. Sensing of the charge then occurs while the electrode remains in its floating condition. Subsequently, a clock pulse is applied to the sensor electrode…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.