Patent ID: 8177426

Claim:
A CMOS temperature detection circuit, comprising: a start-up circuit for generating a start-up voltage; a proportional to absolute temperature (PTAT) current generator formed using CMOS technology, coupled to the start-up circuit, for generating a PTAT current, wherein the start-up voltage turns on the PTAT current generator, and wherein the PTAT current generator uses the sub-threshold characteristics of the CMOS technology to generate the PTAT current; a PTAT voltage generator coupled to the PTAT current generator that receives the PTAT current and generates an inverse PTAT voltage (VBE) and a PTAT voltage, wherein first and second alarm values are derived from the PTAT voltage; and a comparator circuit coupled to the voltage generator for comparing the inverse PTAT voltage to the first and second alarm values, respectively, and generating an alarm signal based on the comparison results.