An apparatus and method measure a temperature of a temperature sensing element having a temperature dependent resistance based on a ratio of discharge times of a capacitor through a reference resistance and through the combination of the reference resistance in parallel with the temperature sensing element is disclosed. A reference discharge time is determined by measuring the discharge time of the capacitor from a first voltage to a second voltage through a reference resistance. A temperature evaluation discharge time is determined by measuring the time to discharge the capacitor from the first voltage to the second voltage through the reference resistance in parallel with the temperature sensing element. The ratio of the temperature evaluation discharge time to the reference discharge time is used to determine the temperature and produce a digital representation of the temperature.