This paper presents a compact resistor-based CMOS temperature sensor intended for dense thermal monitoring. It is based on an RC poly-phase filter (PPF), whose temperature-dependent phase shift is read out by a frequency-locked loop (FLL). The PPF's phase shift is determined by a zero-crossing (ZC) detector, allowing the rest of the FLL to be realized in an area-efficient manner. Implemented in a 65-nm CMOS technology, the sensor occupies only 7000 μm2. It can operate from supply voltages as low as 0.85 V and consumes 68 μW. A sensor based on a PPF made from silicided p-poly resistors and metal-insulator-metal (MIM) capacitors achieves an inaccuracy of ±0.12 °C (3σ) from -40 °Cto 85 °C and a resolution of 2.5 mK (rms) in a 1-ms conversion time. This corresponds to a resolution figure-of-merit (FoM) of 0.43 pJ·K2.
Bibliographical noteFunding Information:
Manuscript received May 9, 2018; revised August 7, 2018 and September 12, 2018; accepted September 13, 2018. Date of publication October 8, 2018; date of current version December 21, 2018. This paper was approved by Guest Editor Yong-Ping Xu. This work was supported in part by SK Hynix and in part by the National Research Foundation of Korea (NRF) Grant funded by the Korean Government (NRF-2016-Global Ph.D. Fellowship Program). (Corresponding author: Youngcheol Chae.) W. Choi, Y. Lee, and Y. Chae are with the Department of Electrical and Electronic Engineering, Yonsei University, Seoul 03722, South Korea (e-mail: firstname.lastname@example.org).
All Science Journal Classification (ASJC) codes
- Electrical and Electronic Engineering