A CMOS Temperature Sensor Circuit
T. Ohzone, Tomonori Sadamoto, T. MORISHITA, Kiyotaka Komoku, Toshihiro Matsuda, H. IWATA · IEICE Transactions on Electronics · 2007
A supply voltage (V DD ) independent temperature sensor circuit, which can be realized by the optimum combination of three current modes of n-MOSFETs including the subthreshold current using the feedback scheme from the temperature dependent voltage (V TD ) output to the gates of three n-MOSFETs, was proposed and fabricated by a standard 1.2μm n-well CMOS process. The circuit consists of only 17 MOSFETs without high resistors resulting in a small die area of 0.18 mm 2 . The temperature coefficient TC of the sensor circuit can be controlled by the channel length ratio L4/L 3 of two n-MOSFETs. The average temperature sensor voltage V TS and its typical TC are 1.77 V at V DD = 5.0 V (20°C) and 5.1 mV/°C for V DD = 5.0 ± 1.0 V in the temperature range of -20-100°C in case of L4/L3 = 9, respectively.