| Citation: |
Junyao Ji, Xinao Ji, Ziyu Zhou, Zhichao Dai, Xuhui Chen, Jie Zhang, Zheng Jiang, Hong Zhang. A 16-bit 18-MSPS flash-assisted SAR ADC with hybrid synchronous and asynchronous control logic[J]. Journal of Semiconductors, 2024, 45(6): 062201. doi: 10.1088/1674-4926/23120049
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J Y Ji, X A Ji, Z Y Zhou, Z C Dai, X H Chen, J Zhang, Z Jiang, and H Zhang, A 16-bit 18-MSPS flash-assisted SAR ADC with hybrid synchronous and asynchronous control logic[J]. J. Semicond., 2024, 45(6), 062201 doi: 10.1088/1674-4926/23120049
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A 16-bit 18-MSPS flash-assisted SAR ADC with hybrid synchronous and asynchronous control logic
DOI: 10.1088/1674-4926/23120049
More Information
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Abstract
This paper presents a 16-bit, 18-MSPS (million samples per second) flash-assisted successive-approximation-register (SAR) analog-to-digital converter (ADC) utilizing hybrid synchronous and asynchronous (HYSAS) timing control logic based on an on-chip delay-locked loop (DLL). The HYSAS scheme can provide a longer settling time for the capacitive digital-to-analog converter (CDAC) than the synchronous and asynchronous SAR ADC. Therefore, the issue of incomplete settling or ringing in the DAC voltage for cases of either on-chip or off-chip reference voltage can be solved to a large extent. In addition, the foreground calibration of the CDAC’s mismatch is performed with a finite-impulse-response bandpass filter (FIR-BPF) based least-mean-square (LMS) algorithm in an off-chip FPGA (field programmable gate array). Fabricated in 40-nm CMOS process, the prototype ADC achieves 94.02-dB spurious-free dynamic range (SFDR), and 75.98-dB signal-to-noise-and-distortion ratio (SNDR) for a 2.88-MHz input under 18-MSPS sampling rate.-
Keywords:
- SAR ADC,
- control logic,
- reference ringing,
- DAC incomplete settling
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References
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Proportional views



Junyao Ji got his B.S. degree in microelectronic science and engineering from Xi’an Jiaotong University, Xi’an China, in 2023. His research interests include analog/mixed-signal IC design such as ADC, amplifiers, bandgap references, and so on.
Xinao Ji got his B.S. from Xi'an Jiaotong University in 2023. Now he is a Master student at Xi'an Jiaotong University under the supervision of Prof. Hong Zhang. His research focuses on mixed signal systems and computing in memory.
Hong Zhang received the Ph. D. degree in electronic engineering from Xi’an Jiaotong University, Xi’an China, in 2008. Since 2008, he has been with the Department of Microelectronics at Xi’an Jiaotong University, where he is currently a Professor. From June to September 2009, he was a visiting scholar at KU Leuven and IMEC, Belgium. From Aug. 2016 to Aug. 2017, he was a visiting professor in the Department of Electrical and Computer Engineering, University of Toronto. His research interests include analog/mixed-signal IC design such as ADC, low-power and low-voltage references, bio-medical ICs, and so on.
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