A high speed snap-shot mode readout circuit for QWIP IR FPAs

The design and fabrication of a Snap-shot mode high speed ROIC for GaAs/AlGaAs QWIP FPAs was reported. The snap-shot CTIA input stage with pixel-level skimming increased the readout speed and integrated voltage swing. The column-shared CDS circuits improved the noise and speed performance under low power dissipation. The multiplexed sampling voltage is buffered to output with high speed output buffer amplifier. The experimental ROIC chip of 128times128 array is fabricated using 0.35 um CMOS mixed signal process. The chip has charge capacity of 2.57times10⁶ electrons and transimpedance of 1 times 10⁸Omega. The measurements show that the readout speed is 10 Mbps, the maximum frame rate is 640 frame/s for 128times128 FPAs under the 3.3 V supply voltage.