Patent ID: 8432214

Claim:
A temperature sensing circuit comprising: a comparator having a first input, a second input, and an output; a first temperature sensing element having a first terminal coupled to the first input of the comparator, and a second terminal, the first temperature sensing element for providing a first complementary to absolute temperature (CTAT) voltage; a second temperature sensing element having a first terminal coupled to the second input of the comparator, and a second terminal, the second temperature sensing element for providing a second CTAT voltage; a first reference circuit having an output terminal for providing a first proportional to absolute temperature (PTAT) voltage; a second reference circuit having an output terminal for providing a second PTAT voltage; and a selection circuit for selectively coupling the output terminals of the first reference voltage circuit and the second reference voltage circuit to the second terminal of the second temperature sensing element in response to a selection signal, wherein when the selection signal is a first logic state, the output terminal of the first reference circuit is coupled to the second terminal of the second temperature sensing element for providing a first threshold voltage to the second input of the comparator, and when the selection signal is a second logic state different from the first logic state, a series connection of the first reference circuit and the second reference circuit are coupled to the second terminal of second temperature sensing element for providing a second threshold voltage to the second input of the comparator.