Direct temperature to digital converters with low supply sensitivity for power/thermal management

A temperature to digital converter (TDC) that does not require either a reference generator or an ADC and that exhibits low supply sensitivity, small die area, and low power consumption is introduced. A prototype circuit designed to support power management applications over the [60 °C, 90 °C] temperature range was implemented in an IBM 0.13μm CMOS process with a 1.2V power supply for use as either a temperature trigger or a digital thermometer. Simulation results show the maximum temperature error over this range is less than ±0.5°C. The total silicon area for the TDC is only .004mm2.