Time Domain and Area Efficient Smart Temperature Sensor Exploiting Channel Length Modulation Coefficient

Abstract

This work suggests an all-digital temperature sensor with a high sampling rate that is based on a time-to-digital converter (TDC). Two on-chip voltage-controlled oscillators (VCOs) are used in the design of the sensor core, which senses temperatures between [Formula: see text]C and 200[Formula: see text]C. For digital code conversion, the outputs of the VCO are fed into two asynchronous counters. In both low- and high- resolution modes, the error following two-point calibration is observed between [Formula: see text]C and [Formula: see text]C. The sensor’s ability to function in both high- and low-resolution modes based on conversion time is an important feature. At a sampling frequency of 0.19[Formula: see text]MHz, the maximum resolution achieved is 0.18[Formula: see text]C. Additionally, the sensor has control logic built in to turn off the sensing as soon as the conversion is complete. At 90-nm process, 1.1[Formula: see text]V supply voltage and 27[Formula: see text]C, the proposed sensor occupies [Formula: see text] and consumes [Formula: see text].