Provided are a semiconductor-based temperature sensor and a method of operating the semiconductor-based temperature sensor. A temperature sensor includes an electrical temperature signal generator configured to generate a first electrical temperature signal that changes according to temperature and a second electrical temperature signal that changes according to temperature at a different rate from that of the first electrical temperature signal, a differential signal generator configured to generate a differential electrical temperature signal between the first electrical temperature signal and the second electrical temperature signal, and an analog digital converter (ADC) configured to convert the differential electrical temperature signal into digital temperature information.