A sensing element integrated in a semiconductor material chip has a sensing diode of a junction type configured to be reverse biased so that its junction capacitance is sensitive to the local temperature. A reading stage is coupled to the sensing element for detecting variations of the junction capacitance of the sensing diode and outputting a reading acquisition signal proportional to the local temperature of the sensing diode. The sensing diode has a cathode terminal coupled to a biasing node and an anode terminal coupled to a first input of the reading stage. The biasing node receives a voltage positive with respect to the first input of the reading stage for keeping the sensing diode reverse biased.