Smart Reset Control for Wide-Dynamic-Range LWIR FPAs

A new readout circuit involving a pixel-level reset control was studied for 2-D long-wavelength infrared (LWIR) focal plane arrays. The integration time of each pixel can be optimized individually and automatically. Hence, the readout circuit has a wide dynamic range and good signal-to-noise ratio (SNR) characteristics. The readout circuit was fabricated with a 0.35-μm 2-poly 4-metal CMOS process for a 128 × 128 LWIR HgCdTe array with a pixel size of 50 μm × 50 μm. The smart reset control with two-step background suppression improves the SNR to 87 dB and the dynamic range to 95.8 dB.