{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T02:48:44Z","timestamp":1760237324805,"version":"build-2065373602"},"reference-count":24,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2020,3,29]],"date-time":"2020-03-29T00:00:00Z","timestamp":1585440000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"The Ministry of Education of Korea","award":["2018R1A6A3A01013018"],"award-info":[{"award-number":["2018R1A6A3A01013018"]}]},{"name":"The Ministry of Science &amp; ICT","award":["2017M3C1B2085296"],"award-info":[{"award-number":["2017M3C1B2085296"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This paper presents a reconfigurable time-to-digital converter (TDC) used to quantize the phase of the impedance in electrical impedance spectroscopy (EIS). The TDC in the EIS system must handle a wide input-time range for analysis in the low-frequency range and have a high resolution for analysis in the high-frequency range. The proposed TDC adopts a coarse counter to support a wide input-time range and cascaded time interpolators to improve the time resolution in the high-frequency analysis without increasing the counting clock speed. When the same large interpolation factor is adopted, the cascaded time interpolators have shorter measurement time and smaller chip area than a single-stage time interpolator. A reconfigurable time interpolation factor is adopted to maintain the phase resolution with reasonable measurement time. The fabricated TDC has a peak-to-peak phase error of less than 0.72\u00b0 over the input frequency range from 1 kHz to 512 kHz and the phase error of less than 2.70\u00b0 when the range is extended to 2.048 MHz, which demonstrates a competitive performance when compared with previously reported designs.<\/jats:p>","DOI":"10.3390\/s20071889","type":"journal-article","created":{"date-parts":[[2020,4,1]],"date-time":"2020-04-01T03:44:13Z","timestamp":1585712653000},"page":"1889","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Design of Reconfigurable Time-to-Digital Converter Based on Cascaded Time Interpolators for Electrical Impedance Spectroscopy"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4881-4786","authenticated-orcid":false,"given":"Sounghun","family":"Shin","sequence":"first","affiliation":[{"name":"Foundry Business, Samsung Electronics Co., Ltd., Hwaseong-si, Gyeonggi-do 18448, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0461-6729","authenticated-orcid":false,"given":"Yoontae","family":"Jung","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2580-8543","authenticated-orcid":false,"given":"Soon-Jae","family":"Kweon","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Eunseok","family":"Lee","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jeong-Ho","family":"Park","sequence":"additional","affiliation":[{"name":"System LSI Business, Samsung Electronics Co., Ltd., Hwaseong-si, Gyeonggi-do 18448, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jinuk","family":"Kim","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hyung-Joun","family":"Yoo","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4580-2771","authenticated-orcid":false,"given":"Minkyu","family":"Je","sequence":"additional","affiliation":[{"name":"School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,3,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"22151","DOI":"10.3390\/s150922151","article-title":"Smartphone-based bioelectrical impedance analysis devices for daily obesity management","volume":"15","author":"Choi","year":"2015","journal-title":"Sensors"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Shin, S.-C., Lee, J., Choe, S., Yang, H.I., Min, J., Ahn, K.-Y., Jeon, J.Y., and Kang, H.-G. 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