A 0.026 mm2 Time Domain CMOS Temperature Sensor with Simple Current Source

Abstract

This paper presents a time domain CMOS temperature sensor with a simple current source. This sensor chip only occupies a small active die area of 0.026 mm2 because it adopts a simple current source consisting of an n-type poly resistor and a PMOS transistor and a simple current controlled oscillator consisting of three current starved inverter delay cells. Although this current source is based on a simple architecture, it has better temperature linearity than the conventional approach that generates a temperature-dependent current through a poly resistor using a feedback loop. This temperature sensor is designed in a 0.18 μm 1P6M CMOS process. In the post-layout simulations, the temperature error was measured within a range from −1.0 to +0.7 °C over the temperature range of 0 to 100 °C after two point calibration was carried out at 20 and 80 °C, respectively. The temperature resolution was set as 0.32 °C and the temperature to digital conversion rate was 50 kHz. The energy efficiency is 1.4 nJ/sample and the supply voltage sensitivity is 0.077 °C/mV at 27 °C while the supply voltage varies from 1.65 to 1.95 V.

60–700 K CTAT and PTAT Temperature Sensors with 4H-SiC Schottky Diodes

“…Usually, these detection systems include a series of commercial temperature sensors, which are based on thermocouples [ 3 ] or resistive temperature detectors [ 4 , 5 ]. Their accuracy and reliability are comparable, but neither are competitive with semiconductor-based temperature sensors [ 6 , 7 ], especially those fabricated on robust materials [ 8 , 9 , 10 ]. The increased request for high temperature-capable applications makes research in this domain constantly strive to find alternative solutions, which can satisfy specifications.…”

Categorization and Characterization of Time Domain CMOS Temperature Sensors

“…As the CMOS process scales down and the supply voltage shrinks, the recent trend is to prefer the time domain signals such as the frequency, period and delay time to the voltage and current signals [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. So, the time domain CMOS temperature sensors are holding more attraction than the traditional CMOS temperature sensors based on the voltage and/or current signals.…”