Integrated temperature sensor for reconfigurable radio frequency synthesizer

Temperature variations significantly affect the performance and reliability of RF integrated circuits, which necessitates for thermal management in RF circuits. In this paper, an integrated analog temperature sensor (ATS) which operates with simple, low-cost one-point calibration is proposed. The temperature to voltage conversion is achieved in two steps i.e. temperature to frequency, followed by frequency to voltage conversion. The output voltage can be used to compensate the temperature dependent errors in the high frequency circuits, thereby reducing the performance degradation due to thermal gradient. The proposed ATS exhibits high sensitivity of 1.182 MHz/°C to temperature in the range of -20°C to 120°C. The errors due to supply and process variations after one-point calibration are within ±0.015°C. The integrated sensor was implemented in the 0.13μm CMOS process. It occupies a core area of 0.0076 mm2 while consuming 756 μW from a 1.2 V supply.