Electro-thermal characterization of a differential temperature sensor in a 65 nm CMOS IC: Applications to gain monitoring in RF amplifiers

This paper reports on the design solutions and the different measurements we have done in order to characterize the thermal coupling and the performance of differential temperature sensors embedded in an integrated circuit implemented in a 65 nm CMOS technology. The on-chip temperature increases have been generated using diode-connected MOS transistors behaving as heat sources. Temperature measurements performed with the embedded sensor are corroborated with an infra-red camera and a laser interferometer used as thermometer. A 2 GHz linear power amplifier (PA) is as well embedded in the same silicon die. In this paper we show that temperature measurements performed with the embedded temperature sensor can be used to monitor the PA DC behavior and RF activity.