A Cryo-CMOS SAR ADC With FIA Sampling Driver Enabled by Cryogenic-Aware Back-Biasing

Journal Article (2023)
Author(s)

G. Kiene (QCD/Sebastiano Lab, TU Delft - QuTech Advanced Research Centre)

Ramon Overwater (TU Delft - QuTech Advanced Research Centre, QCD/Sebastiano Lab)

M. Babaie (TU Delft - Electronics, TU Delft - QuTech Advanced Research Centre)

Fabio Sebastiano (TU Delft - Quantum Circuit Architectures and Technology, TU Delft - QuTech Advanced Research Centre)

Research Institute
QuTech Advanced Research Centre
Copyright
© 2023 G. Kiene, R.W.J. Overwater, M. Babaie, F. Sebastiano
DOI related publication
https://doi.org/10.1109/TCSI.2023.3336566
More Info
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Publication Year
2023
Language
English
Copyright
© 2023 G. Kiene, R.W.J. Overwater, M. Babaie, F. Sebastiano
Research Institute
QuTech Advanced Research Centre
Issue number
3
Volume number
71
Pages (from-to)
1071-1081
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Abstract

This paper presents a floating inverter amplifier (FIA) that performs high-linearity amplification and sampling while driving a 2<inline-formula> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> time-interleaved (TI) SAR ADC, operating from room temperature (RT) down to 4.2 K. The power-efficient FIA samples the continuous-time input signal by windowed integration, thus avoiding the traditional sample-and-hold. Cascode switching, a floating supply and accurate pulse-width timing calibration enable high-speed operation and interleaving. In addition, by exploiting the behavior of CMOS devices at cryogenic temperatures, forward-body-biasing (FBB) is pushed well beyond what is possible at RT to ensure performance down to 4.2 K, and its impact on the performance of cryogenic circuits is analyzed. The resulting ADC, implemented in 40-nm bulk CMOS and including the FIA driver, achieves SNDR<inline-formula> <tex-math notation="LaTeX">$=$</tex-math> </inline-formula>38.7 dB (38.2 dB), SFDR<inline-formula> <tex-math notation="LaTeX">$&gt;$</tex-math> </inline-formula>50 dB (<inline-formula> <tex-math notation="LaTeX">$&gt;$</tex-math> </inline-formula>50 dB), and FOMW<inline-formula> <tex-math notation="LaTeX">$=$</tex-math> </inline-formula>25.4 fJ/conv-step (31.3 fJ/conv-step) with Nyquist-rate input at 1.0 GS/s (0.9 GS/s) at 4.2 K (RT), respectively.