Inventors:
Arthur L. Morse - Hawthorne CA
Niels A. Thompson - Los Angeles CA
Assignee:
Hughes Aircraft Company - Los Angeles CA
International Classification:
H01J 4014
H01L 2978
Abstract:
A method and circuit for reading out the detector signal current from an infrared focal plane array by converting the detector current into a precisely proportional charge packet which is injected into the channel of a charge-coupled device (CCD). In a preferred embodiment the circuit comprises a capacitive feedback transimpedance amplifier 30 (or similar infrared detector signal encoding circuit) coupled to a precision CCD charge-injection circuit 10 formed on a semiconducting substrate 12. A surface potential well 50 underneath a reservoir gate electrode 80 is filled with charge that is initially kept in place by a channel stop 14 and a potential barrier 62. When the detector signal is applied to signal gate electrode 60, the potential barrier 62 is lowered and a precisely proportional amount of charge fills a store potential well 48 underneath a store gate electorde 85. At an appropriate time the charge in the storage potential well 48 is transferred to CCD channel 90 by means of a clock pulse applied to a transfer gate electorde 100.