US Patent 7212064 Methods and systems for measuring temperature using digital signals

Methods and systems for measuring temperature are described. A voltage source supplies a voltage. A current source supplies an amount of current that is controlled using a digital input signal. A diode is coupled to the current source. A comparator has a first input coupled to the voltage source and a second input coupled to a node between the current source and the diode. The digital input signal is changed to a value that causes an output of the comparator to change state. A value of the digital input signal is determined for each of two voltages. The values of the digital input signal and the two voltage values (or the difference between the two voltages) are used as inputs to a temperature calculation.