Sub-threshold-based semiconductor temperature sensor

A method, comprising:

• conducting a sub-threshold current through a sensor transistor having its gate and source tied together;
• mirroring the leakage current through a diode-connected transistor to produce an output voltage at a drain of the diode-connected transistor while maintaining a drain voltage for the sensor transistor to equal the output voltage, wherein the diode-connected transistor is located at a first location on a semiconductor die;
• and
• using the output voltage to determine a temperature for the first location on the semiconductor die, wherein mirroring the sub-threshold leakage current through the diode-connected transistor further comprises connecting the diode-connected transistor to the output node through a first switch.

A temperature sensor, comprising:

• an NMOS sensor transistor having a source and a gate coupled to ground, wherein the sensor transistor is configured to conduct a leakage current;
• a first NMOS diode-connected transistor having a drain and a gate coupled to an output node for the temperature sensor and having a source coupled to ground;
• a first NMOS transistor having a source coupled to a drain of the NMOS sensor transistor,
• a PMOS diode-connected transistor having a drain coupled to a drain of the first NMOS transistor and having a source coupled to a power supply node;
• a first PMOS transistor having a source coupled to the power supply node and having a gate coupled to a gate for the PMOS diode-connected transistor;
• and
• a second NMOS diode-connected transistor having a source connected to the output node for the temperature sensor, a gate connected to a gate for the first NMOS transistor, and having a drain coupled to a drain for the first PMOS transistor.