An all-digital on-chip abnormal temperature warning sensor for dynamic thermal management

In this paper, an all-digital on-chip abnormal temperature warning sensor (ATWS) which can tolerate process and voltage variations after four-point calibration is presented. The proposed ATWS uses the delay ratios among three ring oscillators to build up a relative reference modeling (RRM) temperature sensor. Then the process variations can be eliminated after four-point calibration. In addition, the operational voltage can be estimated by the RRM. Thus, the proposed ATWS can use a linear model to compute the chip temperature even with voltage variations. The proposed ATWS is implemented in a 90nm CMOS process, and the active area is 0.0625mm². It can achieve temperature error smaller than ±3.66°C within the range of 40°C to 70°C, and 0.9V to 1.1V. The power consumption is 530μW at 4k sample/s.