A Two-Stage Capacitive-Feedback Differencing Amplifier for Temporal Contrast IR Sensors

This paper presents a small-area, ultra low-power, low-mismatch differencing amplifier for use in transient pixels of micro-bolometer based temporal contrast IR sensors. The two-stage capacitive-feedback amplifier works in the sub-threshold domain, has a voltage gain of 46dB, a 3dB bandwidth of about 10 kHz and consumes 85nW of static power. The amplifier circuit has been fabricated in a 0.35μm standard CMOS process and consumes less than 2000μm
²
of silicon area, enabling a square pixel size of 50μm x 50μm.