Compact and Supply-V oltage-Scalable Temperature Sensors for Dense On-Chip

Abstract

This paper presents compact and voltage-scalable temperature sensor circuits for implementing dynamic thermal management (DTM) in high-performance microprocessors and Systems-on-Chips (SoC). The proposed sensor front ends require only 6 to 8 NMOS transistors, resulting in more than one order of magnitude smaller area than the previous state of the art. The sensor supply voltage can be scaled down to 0.6 V , so it can be integrated with digital circuits employing a dynamic-voltage- scaling technique without additional power distribution and regu- lation. Sensor front ends with three different sizes (115, 279, and 400 µm 2) and their back ends have been prototyped in a 65 nm CMOS technology. The measurement results of the 279 µm2 front end at 0.6 V show a worst-case error of 7.0 ◦C across 64 instances 0◦C to 100◦C after a low-cost one-temperature-point calibration. With the same conditions, the measurements of the 400 µm2 front end show a worst-case error of 5.4 ◦C across 64 instances. The compact sensor designs make it possible to integrate an order of magnitude more sensors on a chip with little additional overhead and thereby enable very dense thermal monitoring in digital VLSI systems.