An electronic device for estimating a temperature value of a thermistor includes a first signal port, an analog-to-digital converter, and a processing circuit. When the thermistor is coupled to the first signal port of the electronic device, the processing circuit is arranged to operate in a first switching condition to detect and generate a first voltage difference to the analog-to-digital converter, to operate in a second switching condition to detect and generate a second voltage difference to the analog-to-digital converter; and, the analog-to-digital converter is arranged to determine a resistance value of the thermistor based on the first voltage difference compared to the second voltage difference and to generate the estimated temperature value according to the determined resistance value.