A 1.5-MHz BW 81.2-dB SNDR Dual-Residue Pipeline ADC With a Fully Dynamic Noise-Shaping Interpolating-SAR ADC

Abstract

This article presents an energy-efficient high-resolution dual-residue (D-R) pipelined-successive approximation register (SAR) analog-to-digital converter (ADC), with a backend capacitive interpolating SAR ADC incorporated with noise-shaping (NS) capability. The residue amplifier design could be simplified as the residue is pre-amplified by the amplifier for the kT/C-noise cancellation. Moreover, the proposed segmented digital-to-analog converter (DAC) structure overcomes parasitic capacitance limitations in the capacitive interpolation, improving resolution along with the gain-error-free advantage of the D-R structure. Fabricated in a 180-nm CMOS technology, the prototype ADC achieves an 81.2-dB signal-to-noise and distortion ratio (SNDR) and an 89.9-dB spurious-free dynamic range (SFDR) in a 1.5-MHz bandwidth (BW) at an over-sampling ratio (OSR) of 8 with a 170.4-dB SNDR Schreier figure-of-merit (FoM) without any calibration.