Patent ID: 7484886

Claim:
An on-chip temperature sensing circuit comprising: a single chip; a comparator on said chip; a first temperature sensor at a specific location on said chip, said first temperature sensor being electrically connected to said comparator and adapted to produce a first output that is temperature-sensitive and to transmit said first output to said comparator; a second temperature sensor on said chip, said second temperature sensor being electrically connected to said comparator and being adapted to produce a second output that is temperature-sensitive and to transmit said second output to said comparator; a heater on said chip, said heater being thermally coupled to said second temperature sensor and comprising at least one diffused semiconductor layer and said second temperature sensor being embedded within said at least one diffused semiconductor layer, wherein said comparator is adapted to compare said first output to said second output, to output a current, and to drive said heater with said current until said second output equals said first output; and a register adapted to record an amount of said current required to drive said heater until said second output equals said first output, said amount being indicative of a temperature at said specific location on said chip.