Backside illuminated CMOS-TDI line scan sensor for space applications

A multi-spectral backside illuminated Time Delayed Integration Radiation Hardened line scan sensor utilizing CMOS technology was designed for continuous scanning Low Earth Orbit small satellite applications. The sensor comprises a single silicon chip with 4 independent arrays of pixels where each array is arranged in 2600 columns with 64 TDI levels. A multispectral optical filter whose spectral responses per array are adjustable per system requirement is assembled at the package level. A custom 4T Pixel design provides the required readout speed, low-noise, very low dark current, and high conversion gains. A 2-phase internally controlled exposure mechanism improves the sensor's dynamic MTF. The sensor high level of integration includes on-chip 12 bit per pixel analog to digital converters, on-chip controller, and CMOS compatible voltage levels. Thus, the power consumption and the weight of the supporting electronics are reduced, and a simple electrical interface is provided. An adjustable gain provides a Full Well Capacity ranging from 150,000 electrons up to 500,000 electrons per column and an overall readout noise per column of less than 120 electrons. The imager supports line rates ranging from 50 to 10,000 lines/sec, with power consumption of less than 0.5W per array. Thus, the sensor is characterized by a high pixel rate, a high dynamic range and a very low power. To meet a Latch-up free requirement RadHard architecture and design rules were utilized. In this paper recent electrical and electro-optical measurements of the sensor's Flight Models will be presented for the first time.