Patent ID: 7331708

Claim:
A frequency ratio digitizing temperature sensor comprising: a temperature sensing circuit providing a current proportional to absolute temperature (PTAT current) and a second current complementary to absolute temperature (CTAT current); an input generation circuit coupled to the temperature sensing circuit to receive the PTAT current and the CTAT current, the input generation circuit generating a first current from the weighted sum of the PTAT current and the CTAT current, the first current being first order temperature independent, the input generation circuit further generating a first corrected current being the sum of the first current and a first portion of the PTAT current, the input generation circuit providing a first output current indicative of the PTAT current, a first output voltage generated by applying the first corrected current to a first resistor, a second output current indicative of the first corrected current, and a second output voltage generated by applying the first current to a second resistor; and a frequency ratio analog-to-digital converter including a data oscillator receiving the first output current and the first output voltage and a reference oscillator receiving the second output current and the second output voltage, the frequency ratio analog-to-digital converter generating a linearity-corrected temperature output signal.