A Sensor System to Detect Positive and Negative Current-Temperature Dependences

摘要

We present a sensor system that determines if the circuit current–temperature $(I - T)$ dependence is positive or negative. While prior temperature sensors can prevent overheating and temperature-induced timing failures in systems with negative $I - T$ dependences, the proposed sensor system can prevent these issues in systems with negative or positive $I - T$ dependences. This capability will become increasingly critical as technology scaling results in positive $I - T$ dependences occurring at near-nominal operating voltages. The fabricated sensor system occupies $ < 0.05 hbox{mm}^{2}$, consuming 310 nJ per sample with 20- $muhbox{s}$ latency in 0.35- $muhbox{m}$ technology. A process variation compensation unit is presented for the calibration of the temperature sensor, which has a temperature nonlinearity of as low as 0.2%. Sensor functionality is verified over a temperature range of 5 $^{circ}hbox{C}$–80 $^{circ}hbox{C}$ and a voltage range of 0.6–3.3 V. The system is shown to achieve this improved functionality while maintaining comparable area, energy, and accuracy with alternative temperature sensor designs.