{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,11]],"date-time":"2026-02-11T18:09:00Z","timestamp":1770833340148,"version":"3.50.1"},"reference-count":27,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2017,6,7]],"date-time":"2017-06-07T00:00:00Z","timestamp":1496793600000},"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>The use of MEMS sensors has been increasing in recent years. To cover all the applications, many different readout circuits are needed. To reduce the cost and time to market, a generic capacitance-to-digital converter (CDC) seems to be the logical next step. This work presents a configurable CDC designed for capacitive MEMS sensors. The sensor is built with a bridge of MEMS, where some of them function with pressure. Then, the capacitive to digital conversion is realized using two steps. First, a switched-capacitor (SC) preamplifier is used to make the capacitive to voltage (C-V) conversion. Second, a self-oscillated noise-shaping integrating dual-slope (DS) converter is used to digitize this magnitude. The proposed converter uses time instead of amplitude resolution to generate a multibit digital output stream. In addition it performs noise shaping of the quantization error to reduce measurement time. This article shows the effectiveness of this method by measurements performed on a prototype, designed and fabricated using standard 0.13 \u00b5m CMOS technology. Experimental measurements show that the CDC achieves a resolution of 17 bits, with an effective area of 0.317 mm2, which means a pressure resolution of 1 Pa, while consuming 146 \u00b5A from a 1.5 V power supply.<\/jats:p>","DOI":"10.3390\/s17061312","type":"journal-article","created":{"date-parts":[[2017,6,7]],"date-time":"2017-06-07T10:01:20Z","timestamp":1496829680000},"page":"1312","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":27,"title":["A Capacitance-To-Digital Converter for MEMS Sensors for Smart Applications"],"prefix":"10.3390","volume":"17","author":[{"given":"Javier","family":"P\u00e9rez Sanjurjo","sequence":"first","affiliation":[{"name":"Electronic Technology Department, Carlos III University of Madrid, Madrid 28911, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0338-9624","authenticated-orcid":false,"given":"Enrique","family":"Prefasi","sequence":"additional","affiliation":[{"name":"Electronic Technology Department, Carlos III University of Madrid, Madrid 28911, Spain"}]},{"given":"Cesare","family":"Buffa","sequence":"additional","affiliation":[{"name":"Infineon Technologies, RF &amp; Sensors, Villach 9500, Austria"}]},{"given":"Richard","family":"Gaggl","sequence":"additional","affiliation":[{"name":"Infineon Technologies, RF &amp; Sensors, Villach 9500, Austria"}]}],"member":"1968","published-online":{"date-parts":[[2017,6,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"3983","DOI":"10.1109\/TIE.2012.2210958","article-title":"Z-Axis Magnetometers for MEMS Inertial Measurement Units Using an Industrial Process","volume":"60","author":"Langfelder","year":"2013","journal-title":"IEEE Trans. Ind. Electron."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Xia, S., Makinwa, K., and Nihtianov, S. (2012, January 19\u201323). A capacitance-to-digital converter for displacement sensing with 17b resolution and 20\u03bcs conversion time. Proceedings of the International Solid-State Circuits Conference Digest of Technical Papers, San Francisco, CA, USA.","DOI":"10.1109\/ISSCC.2012.6176973"},{"key":"ref_3","unstructured":"Oh, S., Jung, W., Yang, K., Blaauw, D., and Sylvester, D. (2014, January 10\u201313). 15.4b incremental sigma-delta capacitance-to-digital converter with zoom-in 9b asynchronous SAR. Proceedings of the Symposium on VLSI Circuits Digest of Technical Papers, Honolulu, HI, USA."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Tan, Z., Chae, Y., Daamen, R., Humbert, A., Ponomarev, Y.V., and Pertijs, M.A.P. (2012, January 13\u201315). A 1.2V 8.3nJ energy-efficient CMOS humidity sensor for RFID applications. Proceedings of the Symposium on VLSI Circuits Digest of Technical Papers, Honolulu, HI, USA.","DOI":"10.1109\/VLSIC.2012.6243771"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Jung, W., Jeong, S., Oh, S., Sylvester, D., and Blaauw, D. (2015, January 22\u201326). 27.6 A 0.7pF-to-10nF fully digital capacitance-to-digital converter using iterative delay-chain discharge. Proceedings of the International Solid-State Circuits Conference Digest of Technical Papers, San Francisco, CA, USA.","DOI":"10.1109\/ISSCC.2015.7063137"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1703","DOI":"10.1109\/JSSC.2012.2191212","article-title":"An Energy-Efficient 15-Bit Capacitive-Sensor Interface Based on Period Modulation","volume":"47","author":"Tan","year":"2012","journal-title":"J. Solid-State Circuits"},{"key":"ref_7","unstructured":"Sanjurjo, J.P., and Prefasi, E. (July, January 29). A high-sensitivity reconfigurable integrating dual-slope CDC for MEMS capacitive sensors. Proceedings of the 11th Conference on Ph.D. Research in Microelectronics and Electronics (PRIME), Glasgow, UK."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"612","DOI":"10.1049\/el.2009.0744","article-title":"Noise-shaped integrating quantisers in \u0394\u03a3 modulators","volume":"45","author":"Maghari","year":"2009","journal-title":"Electron. Lett."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"526","DOI":"10.1049\/el.2012.3776","article-title":"Multistage ADC based on integrating quantiser and gated ring oscillator","volume":"49","author":"Prefasi","year":"2013","journal-title":"Electron. Lett."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Cannillo, F., Prefasi, E., Hern\u00e1ndez, L., Pun, E., Yazicioglu, F., and van Hoof, C. (2011, January 12\u201316). 1.4V 13\u03bcW 83dB DR CT-\u03a3\u0394 modulator with Dual-Slope quantizer and PWM DAC for biopotential signal acquisition. Proceedings of the European Solid-State Circuits Conference (ESSCIRC), Helsinki, Finland.","DOI":"10.1109\/ESSCIRC.2011.6044958"},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Senturia, S.D. (2001). Microsystem Design, Kluwer Academic Publishcers.","DOI":"10.1007\/b117574"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1584","DOI":"10.1109\/5.542410","article-title":"Circuit techniques for reducing the effects of op-amp imperfections: Autozeroing, correlated double sampling, and chopper stabilization","volume":"84","author":"Enz","year":"1996","journal-title":"Proc. IEEE"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1581","DOI":"10.1109\/JSSC.2015.2435736","article-title":"A Dual-Slope Capacitance-to-Digital Converter Integrated in an Implantable Pressure-Sensing System","volume":"50","author":"Oh","year":"2015","journal-title":"J. Solid-State Circuits"},{"key":"ref_14","unstructured":"(2017, March 02). Circuit Techniques for Reducing the Effects of Op-Amp Imperfections: Autozeroing, Correlated Double Sampling, and Chopper Stabilization. Available online: http:\/\/www.analog.com\/media\/en\/technical-documentation\/data-sheets\/AD7745_7746."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Gozzini, F., Ferrari, G., and Sampietro, M. (2009, January 8\u201312). An instrument-on-chip for impedance measurements on nanobiosensors with attoFarad resoution. Proceedings of the International Solid-State Circuits Conference Digest of Technical Papers, San Francisco, CA, USA.","DOI":"10.1109\/ISSCC.2009.4977450"},{"key":"ref_16","unstructured":"Amini, B.V., Pourkamali, S., and Ayazi, F. (2004, January 15\u201319). A 2.5V 14-bit \u03a3\u0394 CMOS-SOI capacitive accelerometer. Proceedings of the International Solid-State Circuits Conference Digest of Technical Papers, San Francisco, CA, USA."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Tan, Z., Daamen, R., Humbert, A., Souri, K., Chae, Y., Ponomarev, Y.V., and Pertijs, M.A.P. (2011, January 14\u201316). A 1.8V 11\u03bcW CMOS smart humidity sensor for RFID sensing applications. Proceedings of the Asian Solid-State Circuits Conference Digest of Technical Papers, Jeju, Korea.","DOI":"10.1109\/ASSCC.2011.6123615"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"130","DOI":"10.1109\/TCSI.2006.887978","article-title":"Ultra-Low-Power Interface Chip for Autonomous Capacitive Sensor Systems","volume":"54","author":"Bracke","year":"2007","journal-title":"IEEE Tran. Circuits Syst. I Regul. Pap."},{"key":"ref_19","first-page":"90","article-title":"A Delta\u2013Sigma Interface Circuit for Capacitive Sensors with an Automatically Calibrated Zero Point","volume":"58","author":"Shin","year":"2011","journal-title":"IEEE Trans. Circuits Syst. II Express Briefs"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Sanyal, A., and Sun, N. (2016, January 12\u201315). A 55fJ\/conv-step hybrid SAR-VCO \u0394\u03a3 capacitance-to-digital converter in 40nm CMOS. Proceedings of the European Solid-State Circuits Conference (ESSCIRC), Lausanne, Switzerland.","DOI":"10.1109\/ESSCIRC.2016.7598322"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Ha, H., Sylvester, D., Blaauw, D., and Sim, J.Y. (2014, January 9\u201313). 12.6 A 160nW 63.9fJ\/conversion-step capacitance-to-digital converter for ultra-low-power wireless sensor nodes. Proceedings of the International Solid-State Circuits Conference Digest of Technical Papers, San Francisco, CA, USA.","DOI":"10.1109\/ISSCC.2014.6757408"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Jiang, H., Wang, Z., Liu, L., Zhang, C., and Wang, Z. (2012, January 5\u20138). A combined low power SAR capacitance-to-digital\/analog-to-digital converter for multisensory system. Proceedings of the International Midwest Symposium on Circuits and Systems (MWSCAS), Boise, ID, USA.","DOI":"10.1109\/MWSCAS.2012.6292191"},{"key":"ref_23","unstructured":"Xiao, Y., Zhang, T., Mak, P.I., Law, M.K., and Martins, R.P. (2012, January 28\u201330). A 0.8 \u00b5W 8-bit 1.5~20-pF-input-range capacitance-to-digital converter for lab-on-chip digital microfluidics systems. Proceedings of the Biomedical Circuits and Systems Conference (BioCAS), Hsinchu, China."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Danneels, H., Coddens, K., and Gielen, G. (2011, January 12\u201316). A fully-digital, 0.3V, 270 nW capacitive sensor interface without external references. Proceedings of the European Solid-State Circuits Conference (ESSCIRC), Helsinki, Finland.","DOI":"10.1109\/ESSCIRC.2011.6044963"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3914","DOI":"10.1109\/TIM.2009.2021241","article-title":"Current-Mode Capacitive Sensor Interface Circuit with Single-Ended to Differential Output Capability","volume":"58","author":"Singh","year":"2009","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1884","DOI":"10.1109\/JSSC.2007.903102","article-title":"A Current-Mode, Dual Slope, Integrated Capacitance-to-Pulse Duration Converter","volume":"42","author":"Bruschi","year":"2007","journal-title":"IEEE J. Solid-State Circuits"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1905","DOI":"10.1109\/TCSI.2014.2298275","article-title":"88-uA 1-MHz Stray-Insensitive CMOS Current-Mode Interface IC for Differential Capacitive Sensors","volume":"61","author":"Scotti","year":"2014","journal-title":"IEEE Trans. Circuits Syst. I Regul. Pap."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/6\/1312\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:38:13Z","timestamp":1760207893000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/6\/1312"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,6,7]]},"references-count":27,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2017,6]]}},"alternative-id":["s17061312"],"URL":"https:\/\/doi.org\/10.3390\/s17061312","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,6,7]]}}}