A 2.5mW 12MHz-BW 69dB SNDR Passive Bandpass ΔΣ ADC with Highpass Noise-Shaping SAR Quantizers

Abstract

A 4th-order passive bandpass Δ Σ modulator (BPDSM) using a 2- path transformation structure is presented. The proposed BPDSM replaces a power-hungry resonator with a z-to-z2-transformed passive loop filter. The prototype bandpass Δ Σ ADC provides a wide intermediate frequency (IF) range of 1.25MHz to 60MHz. The measured SNDR is 69dB with a power consumption of 2.5mW at 12MHz bandwidth when its highest sampling rate is 240MS/s.