Multiple channel readout circuit optimized for a cryogenically operated IR sensor head
US4862002A · kind A · utility
Inventors
Key dates
| Filing date | May 31, 1988 |
| Grant date | Aug 29, 1989 |
| Priority date | — |
| Expiry date | May 31, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2005/283
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention relates to a multiple channel readout circuit optimized for a cryogenically operated IR sensor head. The circuit is applicable to the individual channel preamplifiers of a charge injection device (CID) IR sensor. Since the thermal leakage must be minimized, the voltages on the principal current supply path to the individual preamplifiers will vary when a strong signal is present on any channel. Crosstalk is avoided by using a four transistor cascode preamplifier circuit having a source follower output, in which the gate of the transistor, which acts as a load to the two cascoded transistors, is isolated from the drain of the load transistor, connected to a gate load node common to the other channels, and the node connected via a single connection of high thermal impedance to a terminal external to the cryogenic environment, at which filtering may be provided as needed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.