Analog-to-Digital Converters on Infrared Focal Plane Arrays

In this effort we will design a 64x64 element ROIC with on-chip ADCs. The architecture and ADC type will be chosen that best meets the needs of the Army. We will simulate the design at cryogenic and room temperatures. We will design, layout, and fabricate a test chip with pixel readout and digitization circuitry. If the Army wishes, we will test this chip in the option period. On-chip A/D converters may improve signal integrity on the FPA, may simplify processing down-stream from the IR FPA, and may decrease the power consumption of the FPA. We have directly relevant experience that makes us especially qualified to design ADCs for IR FPAs. At Tanner Research, we have designed, fabricated, and successfully demonstrated two CMOS imagers with on-chip ADCs. One design included a single 10-bit flash ADC with a 2D imager, and the other included a bank of somewhat slower 10-bit ADCs with a 1D imager. Both imager chips produce data at 20 million samples per second. Further, we have fabricated a number of micropower ADCs that may be suitable for inclusion on an ROIC. This design phase will prepare us for fabrication of a 64x64 readout IC Phase II.