A CMOS Temperature Sensor With a Voltage-Calibrated Inaccuracy of ± 0.15°C (3σ) From ―55°C to 125°C

• Published in: IEEE journal of solid-state circuits Vol. 48; no. 1; pp. 292 - 301
• Main Authors: SOURI, Kamran, CHAE, Youngcheol, MAKINWA, Kofi A. A
• Format: Conference Proceeding Journal Article
• Language: English
• Published: New York, NY Institute of Electrical and Electronics Engineers 2013; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Calibration; Circuit properties; Design. Technologies. Operation analysis. Testing; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Exact sciences and technology; Integrated circuits; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Signal convertors; Transistors; SAR; Plastic packaging; Junction transistors; Sigma-delta modulation; AD converter; Energy dissipation; Complementary MOS technology; Electronic packaging; Electric power consumption; trimming; Minimum energy; Measurement sensor; AD conversion; Temperature sensor; Calibration; Intelligent sensors; Bipolar transistor; smart sensors; Temperature measurement; Ceramic packaging; Radiofrequency integrated circuits; Low-power electronics; Energy absorption; RFID tag; Room temperature; Radio frequency identification
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/JSSC.2012.2214831

This paper describes the design of a low power, energy-efficient CMOS smart temperature sensor intended for RFID temperature sensing. The BJT-based sensor employs an energy- efficient 2nd-order zoom ADC, which combines a coarse 5-bit SAR conversion with a fine 10-bit ΔΣ conversion. Moreover, a new integration scheme is proposed that halves the conversion time, while requiring no extra supply current. To meet the stringent cost constraints on RFID tags, a fast voltage calibration technique is used, which can be carried out in only 200 msec. After batch calibration and an individual room-temperature calibration, the sensor achieves an inaccuracy of [Formula Omitted] [Formula Omitted] from [Formula Omitted] to 125[Formula Omitted]. Over the same range, devices from a second lot achieved an inaccuracy of [Formula Omitted] [Formula Omitted] in both ceramic and plastic packages. The sensor occupies 0.08 [Formula Omitted] in a 0.16 [Formula Omitted] CMOS process, draws 3.4 [Formula Omitted] from a 1.5 V to 2 V supply, and achieves a resolution of 20 mK in a conversion time of 5.3 msec. This corresponds to a minimum energy dissipation of 27 nJ per conversion.