On-Chip Digital Temperature Sensor for CMOS Image Sensor

Abstract

The Digital Temperature Sensors relies on two main parts: temperature sensor with analogue output and analogue-to-digital converter. The analogue temperature sensor architecture developed in this work consists on having a circuit with MOSFETs producing an output voltage proportional to absolute temperature the most linear possible. This voltage is then converted to a 10 bit digital value by a ramp run-up analogue-to-digital converter. The project was developed in a standard 130nm CMOS process. As result the digital temperature sensor has an area of 0.016mm2 and an accuracy of $\pm 0.175^{\circ}\text{C}$ from −20 °C to 120 °C.