Details

Autor(en) / Beteiligte

• Xing, Kai
• Wang, Wei
• Zhu, Yan
• Chan, Chi-Hang
• Martins, Rui P.

Titel

A Single-Opamp Third Order CT ΔΣ Modulator With SAB-ELD-Merged Integrator and Three-Stage Hybrid Compensation Opamp

Ist Teil von

• IEEE transactions on circuits and systems. I, Regular papers, 2022-01, Vol.69 (1), p.64-74

Ort / Verlag

New York: IEEE

Erscheinungsjahr

2022

Quelle

IEEE/IET Electronic Library (IEL)

Beschreibungen/Notizen

• This paper proposes a 3 rd order continuous-time delta-sigma modulator (CTDSM) with a single amplifier biquad (SAB) and excess loop delay (ELD) merged integrator. The integrator enables a 2 nd order noise-shaping together with ELD compensation with just a single Opamp and feedback DAC. A three-stage Opamp with a hybrid frequency-compensation scheme is presented, which achieves high gain and large unity-gain bandwidth (UGBW) with low power. The circuit secures an extra order noise-shaping through a passive noise-shaping SAR (NS-SAR) quantizer (QTZ) while further incorporating a preliminary sampling and quantization (PSQ) technique, the 1 st order NS QTZ can run at 1.5 GHz with 6b. The design, implemented in 28 nm, obtains 74.4 dB SNDR with 50 MHz bandwidth while consuming 10.4 mW from 1.5 V and 1 V power supplies. The prototype attains a dynamic range of 80.6 dB with a Schreier FOM of 171.2 dB. With the presented integrator and Opamp, the loop filter only consumes 14 % of the total DSM power consumption.