A -50 to 130°C, 38.69 pJ/conv Fully Integrated SAR Temperature Sensor Based on Direct Temperature-Voltage Comparison

Temperature sensors are increasingly used for many applications, including on-chip thermal management and environmental sensors. Such an application requires a large array of temperature sensors, so a small, energy-efficient, and reliable temperature sensor is demanded. Most previous temperature sensors first convert temperature into an analog electrical signal such as voltage, current, delay, and frequency. These signals are transformed again into a final output code by another readout circuit, as shown in Fig. 1 (Top). Designing such a temperature sensor faces two opposite challenges. First, the transducer must be as sensitive to temperature as possible to maximize the amount of perceived temperature information. Secondly, the sensor interface circuit should be insensitive to temperature in order not to affect the temperature measurement.