A snap-shot mode cryogenic readout circuit for QWIP IR FPAs

The design and measurement of a snap-shot mode cryogenic readout circuit (ROIC) for GaAs/AlGaAs QWIP FPAs was reported. CTIA input circuits with pixel level built-in electronic injection transistors were proposed to test the chip before assembly with a detector array. Design optimization techniques for cryogenic and low power are analyzed. An experimental ROIC chip of a 128 x 128 array was fabricated in 0.35 mu m CMOS technology. Measurements showed that the ROIC could operate at 77 K with low power dissipation of 35 mW. The chip has a pixel charge capacity of 2.57 x 10(6) electrons and transimpedance of 1.4 x 10(7) Omega. Measurements showed that the transimpedance non-uniformity was less than 5% with a 10 MHz readout speed and a 3.3 V supply voltage.