High-speed dual-output-channel stage-selectable TDI CCD image sensor for high-resolution a

摘要

Abstract: TDI sensors are a proven means of increasing the responsivity in a line scan imaging application. This paper describes the development of a family of high speed 96 stage TDI sensors. The sensor is available in a high resolution 2048 element version. A 512 element part will also be made. The number of TDI stages in the sensor can be selected in blocks of 6, 12, 24, 48, and 96 stages thus providing optimum sensitivity and performance over a wide range of illumination conditions. The device is fabricated using double metal, triple poly, buried channel, NMOS CCD process. The imaging region is 4-phase, 2-poly for maximum charge storage and optimum MTF. The pixel pitch on the sensor is 13 $mu@m. The sensor employs a dual channel, 2-phase, 2-poly output shift register for high speed read-out. This technique enables halving the driving clock frequency thus reducing the power consumption which can be a severe problem at large data rates. Another benefit of dual channels is that each horizontal CCD (HCCD) pixel corresponds to two vertical CCD (VCCD) registers. As a result the charge storage capacity of the HCCD is doubled without having to increase the register width. The developed sensor operates at a combined data rate of up to 40 MHz. The maximum line speeds are 32,000 and 14,000 lines/sec for the 512 and 2048 element parts respectively. Methods to reduce the fixed pattern noise resulting from transfer inefficiencies between the two HCCD channels have been implemented. !7