TY - GEN
T1 - A 118.6fJ/Conversion-Step Two-Step Time-Domain RC-to-Digital Converter With 33nF/10MΩ Range and 53aFrmsResolution
AU - Seong, Hoyong
AU - Jung, Chongsoo
AU - Youn, Donghyun
AU - Lee, Junghyup
AU - Ha, Sohmyung
AU - Je, Minkyu
N1 - Funding Information:
Acknowledgements: This work was supported by the Ministry of Science and ICT, Korea (2020M3C1B8A01111568, IITP-2020-0-01778). The chip fabrication was supported by the IDEC, Korea. References: [1] W. Jung et al., “A 0.7pF-to-10nF fully digital capacitance-to-digital converter using iterative delay-chain discharge,” ISSCC 2015:484-486. [2] A. K. George et al., “A 46nF/10-MΩ range 114-aF/0.37-Ω resolution parasitic-and temperature-insensitive reconfigurable RC-to-digital converter in 0.18-μm CMOS,” IEEE TCAS-I, vol. 69, no. 3, 2022:1171-1184.
Publisher Copyright:
© 2022 IEEE.
PY - 2022
Y1 - 2022
N2 - Sensor readout ICs for internet-of-things (IoT) systems require not only high energy efficiency and resolution but also a wide input range to cover a variety of sensors with different output types and characteristics [1], [2]. Readout methods based on delta-sigma modulation (DSM) [3], [4] and two-step conversion (successive approximation + time-domain (TD) DSM) [5] have been proposed to achieve high resolution and energy efficiency, but these structures suffer from limited input ranges as they convert the sensor output to voltage, whose range is strictly constrained by the given supply rails. Alternatively, a TD readout method converts the sensor output into a TD signal, eliminating the range constraint [1], [2], [6]. However, its resolution is limited by the jitter performance of the oscillator of the counting clock [1]. This resolution issue can be addressed together with a wide input range by a dual-oscillator-based structure utilizing a large oversampling ratio (OSR) [2]. However, a power-hungry high-frequency reference oscillator (R-OSC) should continuously operate to reduce the quantization noise (Q-noise), degrading energy efficiency greatly. Although this structure can reduce both the Q-noise and random noise by sacrificing the readout time, the signal-to-noise ratio (SNR) per energy efficiency is limited by the performance of the oscillator itself. Here, we present a TD 2-stepconversion readout IC achieving a wide input range, high resolution, and high energy efficiency altogether.
AB - Sensor readout ICs for internet-of-things (IoT) systems require not only high energy efficiency and resolution but also a wide input range to cover a variety of sensors with different output types and characteristics [1], [2]. Readout methods based on delta-sigma modulation (DSM) [3], [4] and two-step conversion (successive approximation + time-domain (TD) DSM) [5] have been proposed to achieve high resolution and energy efficiency, but these structures suffer from limited input ranges as they convert the sensor output to voltage, whose range is strictly constrained by the given supply rails. Alternatively, a TD readout method converts the sensor output into a TD signal, eliminating the range constraint [1], [2], [6]. However, its resolution is limited by the jitter performance of the oscillator of the counting clock [1]. This resolution issue can be addressed together with a wide input range by a dual-oscillator-based structure utilizing a large oversampling ratio (OSR) [2]. However, a power-hungry high-frequency reference oscillator (R-OSC) should continuously operate to reduce the quantization noise (Q-noise), degrading energy efficiency greatly. Although this structure can reduce both the Q-noise and random noise by sacrificing the readout time, the signal-to-noise ratio (SNR) per energy efficiency is limited by the performance of the oscillator itself. Here, we present a TD 2-stepconversion readout IC achieving a wide input range, high resolution, and high energy efficiency altogether.
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U2 - 10.1109/A-SSCC56115.2022.9980735
DO - 10.1109/A-SSCC56115.2022.9980735
M3 - Conference contribution
AN - SCOPUS:85146559047
T3 - 2022 IEEE Asian Solid-State Circuits Conference, A-SSCC 2022 - Proceedings
BT - 2022 IEEE Asian Solid-State Circuits Conference, A-SSCC 2022 - Proceedings
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 2022 IEEE Asian Solid-State Circuits Conference, A-SSCC 2022
Y2 - 6 November 2022 through 9 November 2022
ER -