A Dynamic-Biased Resistor-Based CMOS Temperature Sensor With a Duty-Cycle-Modulated Output

This brief presents a resistor-based CMOS temperature sensor with a duty-cycle-modulated output. A dynamic-biased resistive analog front-end (AFE) is proposed to generate voltages with positive and negative temperature dependencies. The voltages are then converted into a digital-friendly duty-cycle-modulated output, which can be proceeded by digital systems directly. Fabricated in a standard 0.13-mu m CMOS process, this sensor occupies a silicon area of 0.025 mm(2) and can operate with a supply voltage as low as 0.8 V. It has a measured inaccuracy of +/- 0.85 degrees C (3 sigma) from -40 degrees C to 85 degrees C fter a two-point calibration. Measured at room temperature, it shows a resolution of 0.226 degrees C in a 0.25-ms conversion time while dissipating 12.5 mu W.