Self-calibrating, wide-range temperature sensor

A temperature sensor circuit, comprising:

• a current reference circuit coupled to a pair of current sources having a ratio of geometries between them, the current reference circuit configured to provide a first reference current and a second reference current, where the first reference current is larger than the second reference current by an amount determined by the ratio of geometries, wherein the current reference circuit comprises:
• a first transistor having a source terminal and a drain terminal, where the source terminal of the first transistor is coupled to a first current source of the pair of current sources;
• a second transistor having a source terminal coupled to a second current source of the pair of current sources, where respective gates of the first and second transistors are coupled together and to a drain terminal of the second transistor;
• a third transistor having a source terminal coupled to the drain terminal of the second transistor;
• and
• a third bipolar transistor having base and collector terminals coupled to a reference voltage and an emitter terminal coupled to the drain terminal of the first transistor;
• and
• a differential sensing path circuit coupled to the current reference circuit, the differential sensing path circuit including at least one pair of oppositely-sized bipolar transistors or diodes, the differential sensing path circuit configured to bias a first bipolar transistor or diode with the first reference current and to bias a second bipolar transistor or diode with the second reference current, where the first bipolar transistor or diode has a smaller cross-sectional area than a cross-sectional area of the second bipolar transistor or diode.