{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T06:17:29Z","timestamp":1788157049716,"version":"build-2803163510"},"reference-count":22,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2026,8,30]],"date-time":"2026-08-30T00:00:00Z","timestamp":1788048000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This work presents a compact, low-power fully CMOS pulse-frequency-modulation (PFM) temperature sensor fabricated in 180 nm technology, supporting a wide \u221260 \u00b0C to 120 \u00b0C sensing range. Subthreshold biasing generates temperature-proportional current, while PFM converts current variations into digital pulse signals to bypass supply voltage swing limitations. The following two core optimizations are proposed: an improved cascode current mirror to suppress channel-length modulation and stabilize thermal current, and a temperature-insensitive monostable circuit eliminating extreme-temperature oscillation failure caused by variable reset pulse width. A four-point off-chip calibration model further compensates static and temperature-dependent loop delay errors. The prototype occupies only 2200 \u03bcm2 core area and consumes 2.9 \u03bcW. With a 5 ms conversion time, it achieves 47 mK RMS temperature resolution, 32 pJ\u00b7K2 resolution FoM and 0.06 pJ\u00b7K\u22122\u00b7mm\u22122 area FoM, with calibrated measurement inaccuracy limited to +1.8\/\u22121.9 \u00b0C (3\u03c3). This RC-free quasi-digital PFM architecture scales well to advanced process nodes and fits aerospace, cryogenic infrared detector and low-power industrial thermal sensing applications.<\/jats:p>","DOI":"10.3390\/s26175506","type":"journal-article","created":{"date-parts":[[2026,8,31]],"date-time":"2026-08-31T05:55:56Z","timestamp":1788155756000},"page":"5506","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A 0.002-mm2, 2.9-\u03bcW Pulse-Frequency-Modulation-Based Temperature Sensor for Wide Sensing Range from \u221260 \u00b0C to 120 \u00b0C"],"prefix":"10.3390","volume":"26","author":[{"given":"Chiyuan","family":"Zhang","sequence":"first","affiliation":[{"name":"Kunming Institute of Physics, Kunming 650223, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"}]},{"given":"Nan","family":"Chen","sequence":"additional","affiliation":[{"name":"Kunming Institute of Physics, Kunming 650223, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"}]},{"given":"Fang","family":"Zhu","sequence":"additional","affiliation":[{"name":"Kunming Institute of Physics, Kunming 650223, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"software","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"}]},{"given":"Shanshan","family":"Li","sequence":"additional","affiliation":[{"name":"Kunming Institute of Physics, Kunming 650223, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"given":"Libin","family":"Yao","sequence":"additional","affiliation":[{"name":"Kunming Institute of Physics, Kunming 650223, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"methodology","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9819-0660","authenticated-orcid":false,"given":"Yuxuan","family":"Luo","sequence":"additional","affiliation":[{"name":"College of Integrated Circuits, Zhejiang University, Hangzhou 310027, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Zhang, C., Chen, N., Hu, D., Zhu, F., Pu, Y., and Yao, L. 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