For the first time, we report on the performances of 4H-SiC p-i-n-diode temperature sensors for operating temperatures between 20.5 and 802 K. In this huge temperature range, three ranges of performance were identified with the limit temperatures at 78.2 and 176.3 K. In each of these ranges, a different dominant current transport mechanism is shown and in this paper, a detailed analysis and discussion are reported. The sensor performances were extracted from VD-T characteristics at different fixed ID values. In particular, at ID = 1 μA and in the temperature range between 78.2 and 802 K, we found a sensor sensitivity of 2.3-3.4 mV/K with a rms temperature error, eT, of less than 4.2 K and the sensor shows an excellent linearity-quantified by the coefficient of determination R2 higher than 0.9993. For even lower temperatures (below 78.2 K), low measurement currents like 10 nA are required leading to a sensitivity of 5.8 mV/K, but a lower linearity (R2 = 0.9095) and an rms temperature error of 9.7 K which makes the sensor only partially usable in the temperature range between 20.5 and 78.2 K. Finally, the sensor performances are compared with other state-of-the-art solutions.