A High-Accuracy, High-Resolution, and Low-Cost All-Digital Temperature Sensor Using a Voltage Compensation Ring Oscillator

This paper proposes an all-digital temperature sensor (ADTS) with a ring oscillator for achieving the following goals: 1) high accuracy; 2) high resolution; 3) low power-supply sensitivity; and 4) low cost. The sensor was developed using a 0.18-mu m standard CMOS process with a 1.8-V supply voltage. The measured results indicate that the proposed ADTS generates a Pearson correlation coefficient (R-2) of 0.99998 and an error of -0.851 degrees C to 0.524 degrees C. The resolution is 0.0582 degrees C/LSB, and the power consumption is < 1 mu J for every sample in the temperature range between 0 degrees C and 100 degrees C. Furthermore, the power-supply sensitivity is < 11.67% between the supply voltage variations (+/- 10%), the temperature sensor system occupies an area of similar to 0.0137 mm(2), and the sensor area is only 0.0004 mm(2).