Patent ID: 6914764

Claim:
An on-chip thermal sensing circuit comprising: a detection circuit located on an integrated circuit (IC) for detecting a focal temperature of said IC; an output of said thermal sensing circuit having a frequency, said frequency being directly related to said local temperature; said detection circuit including a capacitor and a sensing resistor, a resistance of said sensing resistor varying in direct proportion to said local temperature of said IC; a voltage divider for producing a first voltage and a second voltage; a first comparator producing a first output and having a first input and a second input, said first input being coupled to said first voltage and said second input being a current value of a voltage across said capacitor; a second comparator producing a second output and having a first input and a second input, said first input being said current value of said voltage across said capacitor and said second input being coupled to said second voltage; and a latch receiving as its inputs said first output and said second output and producing said output and a third output, said third output being coupled to said detection circuit.