A 200-kHz Bandwidth Second-Order Noise-Shaping SAR ADC using a Differential-Difference Ring Amplifier
Year: 2026
Type: conference-paper
Abstract: Error-feedback noise-shaping (EF NS) SAR ADC nowadays is a popular alternative to discrete-time (DT) deltasigma ADCs due to its simplicity and efficiency. In this paper, we propose a $\mathbf{2}^{\text {nd }}$-order EF NS SAR, implemented with a passive, cap-stacking FIR filter alongside a ring amplifier that operates as a residue amplifier. To avoid the charge stored in FIR and the capacitive DAC (CDAC) from being used up, the ringamplifier-based residue amplifier was modified into a differentialdifference structure, so that it does not take the charge from the preceding stage by sampling its input. Designed in $0.18 \mu \mathrm{~m}$ CMOS technology, the EF NS SAR ADC achieves 84.9 dB SNDR in 200-kHz bandwidth, operating under 1.2 V supply and 10.24 MS/s sampling rate, while consuming $521.5 \mu \mathrm{~W}$ of power.
Institution: Oregon State University
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W7212287091