TY - GEN
T1 - A 74.5-dB DR 1.25-MHz BW Continuous-Time Delta-Sigma ADC Using Low-Noise Feedback DAC with Optimized Barrel Shifter
AU - Fu, Zhigang
AU - Fu, Renjie
AU - Shi, Linxu
AU - Xu, Yilin
AU - Zhang, Deming
AU - Zhang, Hui
N1 - Publisher Copyright:
© 2026 IEEE.
PY - 2026
Y1 - 2026
N2 - This paper presents a 4-bit, 3rd-order continuous -time (CT) delta-sigma modulator (DSM) for through-wall radar (TWR) applications, achieving a 1.25-MHz bandwidth. A low-noise, current-steering digital-to-analog converter (DAC) is proposed, which employs source degeneration and noise filtering to reduce its output current noise power by 2.6 dB. To further enhance linearity, an optimized barrel shifter is implemented to perform a data-weighted averaging (DWA) algorithm based on a modulo-15 element rotation scheme. Additionally, power-efficient operational amplifiers (OPAs) utilizing a hybrid Miller and feedforward compensation scheme are employed in the second and third integrators. Fabricated in 40-nm CMOS process, the proposed Analog-to-Digital Converter (ADC) achieves a measured dynamic range (DR) of 74.5 dB and a spurious-free dynamic range (SFDR) of 80.1 dB. It consumes 6.5mW from a 1.2-V supply and occupies a core active area of 0.1 mm2.
AB - This paper presents a 4-bit, 3rd-order continuous -time (CT) delta-sigma modulator (DSM) for through-wall radar (TWR) applications, achieving a 1.25-MHz bandwidth. A low-noise, current-steering digital-to-analog converter (DAC) is proposed, which employs source degeneration and noise filtering to reduce its output current noise power by 2.6 dB. To further enhance linearity, an optimized barrel shifter is implemented to perform a data-weighted averaging (DWA) algorithm based on a modulo-15 element rotation scheme. Additionally, power-efficient operational amplifiers (OPAs) utilizing a hybrid Miller and feedforward compensation scheme are employed in the second and third integrators. Fabricated in 40-nm CMOS process, the proposed Analog-to-Digital Converter (ADC) achieves a measured dynamic range (DR) of 74.5 dB and a spurious-free dynamic range (SFDR) of 80.1 dB. It consumes 6.5mW from a 1.2-V supply and occupies a core active area of 0.1 mm2.
KW - Barrel Shifter
KW - Continuous-Time (CT)
KW - Delta-Sigma Modulator
KW - Dynamic Element Matching (DEM)
KW - Low-Noise DAC
KW - Through-Wall Radar (TWR)
UR - https://www.scopus.com/pages/publications/105043431707
U2 - 10.1109/ISCAS66217.2026.11561935
DO - 10.1109/ISCAS66217.2026.11561935
M3 - 会议稿件
AN - SCOPUS:105043431707
T3 - Proceedings - IEEE International Symposium on Circuits and Systems
SP - 3808
EP - 3811
BT - ISCAS 2026 - 2026 IEEE International Symposium on Circuits and Systems
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2026 IEEE International Symposium on Circuits and Systems, ISCAS 2026
Y2 - 24 May 2026 through 27 May 2026
ER -