Patent ID: 6292050
Filing Date: 2001-09-18
Classification: A61N,G05F

Abstract:
A reference circuit comprising:a first bias circuit including less than three series-coupled diodes comprising first and second series-coupled diodes biased by at least one first current source, providing a first temperature dependent voltage across the series-combination of the first and second diodes;a second bias circuit including a resistor and less than three series-coupled diodes comprising third and fourth series-coupled diodes biased by at least one second current source, providing a second temperature dependent voltage across the series-combination of the third and fourth diodes, wherein the second temperature dependent voltage has a different temperature dependence than the first temperature dependent voltage; anda complementary metal oxide semiconductor (CMOS) differential input first amplifier having first and second inputs electrically coupled to the respective first and second temperature dependent voltages of the respective first and second bias circuits, and having an output providing a proportional to absolute temperature (PTAT) reference current through the resistor by measuring a difference between the first and second temperature dependent voltageswherein a power supply voltage provided to the first amplifier is between 1.3 volts and 2.1 volts.