High sensitivity focal plane array-based laser detection and ranging receiver with pixel combining readout scheme

This study introduces the pixel combining readout scheme for high sensitivity focal plane array (FPA)-based laser detection and ranging (LADAR) receiver circuits. The transimpedance combining amplifier (TCA) combines all the photocurrents from several photodetectors with a single output signal. Owing to the proposed readout scheme, the FPA-based LADAR receiver effectively reads the large size of photodetector without bandwidth deterioration, resulting in high sensitivity and accurate range information. A prototype chip was fabricated by a standard 0.18-μm CMOS process. The total power consumption of this chip, including the output buffer, is 37.4 mW from a 1.8 V supply. The prototype chip for a photodetector with parasitic capacitance of 6 pF achieves an input referred noise current spectral density of 4.71 pA/√Hz with 310 MHz bandwidth, a transimpedance gain of 67.6 dB·Ω, and a minimum detectable signal of 340 nA.