Focal Plane Signal Processing Requirements For Scanned Charge-Injection Device (CID) Arrays
D. J. MacLennan, M.K. Quick, S. W. Lefort · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1980
The major requirements in focal plane signal processing for scanned CID's are the low noise detection of signal charge, the enhancement of signal to noise ratio, the rejection of background signal and the low noise multiplexing of data onto a few signal lines. For implementation on the focal plane, these functions must be designed to operate at cryogenic temperatures, where bipolar and JFET technologies are inappropriate for reasons of low gain or high noise. It is proposed that a combination of linear MOS and Charge Coupled Device technology is the most appropriate for implementing scanned CID systems and in this paper the design and evaluation of these circuit functions are discussed. The implementation of an optimum design for a low noise MOS preamplifier is first considered followed by a discussion of the design aspects of a time delay and integrate device. The novel implementation of a high pass filter in conjunction with a low noise multiplexer completes the focal plane design. Experimental results obtained from a number of fabricated devices will be presented to illustrate the relative maturity of the design approach.