A 15nV/√Hz noise 0.2μV offset chopper conditioning amplifier for monolithic infrared sensing systems

Conventional chopper conditioning amplifiers with a differential architecture are largely inappropriate for the monolithic infrared sensing systems with the requirements of single-ended architecture, low power, and yet low noise and low offset. In this paper, a novel chopper amplifier is proposed to satisfy all the aforesaid requirements. This is achieved by means of a novel chopper demodulator that not only incurs no hardware overhead but also inherently suppresses noise and offset. On the basis of computer simulations, the proposed chopper amplifier features very low input referred noise (15nV/√Hz), very low input referred offset (0.2μV), high Signal-to-Noise Ratio (~87dB) and high Common Mode Rejection Ratio (98dB), and dissipates low quiescent current (57.6μA). When compared to reported differential chopper amplifiers, the proposed amplifier depicts very competitive Figure-Of-Merit.