A 114.5-dB DR, 184.6-dB FoMDR Discrete-Time Self-Zoom ADC

This brief describes a self-zoom analog-to-digital converter (ADC), where zooming function is implemented by subtracting quantizer output with digital processing from input signal. Self-zoom employs a digital filter instead of a coarse ADC for zoom implementation, resulting in improved efficiency. In addition, this work uses a 2.25-bit quantizer to achieve 5-bit self-zoom and utilizes a fast startup scheme to optimize the initiation speed. The prototype ADC was manufactured in 0.18 μm CMOS technology and occupies an area of 0.34 mm2. In a 3.9 kHz bandwidth, the ADC achieves a DR of 114.5 dB, a SNDR of 108.7 dB, and consumes 385 μW under a 1.8V supply. This results in state-of-the-art power efficiency, in terms of FoMDR of 184.6 dB and FoMSNDR of 178.8 dB.