A temperature sensor having calibration function according to temperature, a method of operating the same, and a device including the same are provided. The temperature sensor includes a reference circuit configured to generate at least one temperature information signal that varies according to a temperature, and generate at least one reference signal that is substantially constant relative to the temperature; and a digital temperature generator configured to receive the at least one temperature information signal and the at least one reference signal generated by the reference circuit, and generate a digital temperature information signal indicative of the temperature based on the at least one temperature information signal and the at least one reference signal, wherein one of the reference circuit and the digital temperature generator is configured to receive a calibration signal and adjust the at least one reference signal based on the calibration signal.