A Large Area TDI Image Sensor for Low Light Level Imaging

Abstract

A 1030 X 128 element time delay and integration (TDI) CCD image sensor has been developed for low-light-level (L/sup 3/) imaging applications. For L/sup 3/ imaging, output is derived from a high-gain low-noise floating-gate amplifier (FGA). For larger input signal levels, a second, resettable floating-gate amplifier (RFGA) with lower gain and wider dynamic range provides output in parallel to the FGA. The device features four-phase buried-channel construction and a polysilicon gate design tailored to produce optimum broad-band responsivity. Input signal levels of 500 electrons have been successfully imaged and amplifier noise levels of approximately 20 electrons have been observed.