Patent ID: 8167485

Claim:
A circuit for producing a digital temperature reading, comprising: a transistor (Q 1 ) including a base, an emitter and a collector, where the base is connected to the collector, and a current path is between the emitter and the collector; one or more current sources and one or more switches to selectively provide a first amount of current (I 1 ) and a second amount of current (I 2 ) to the current path of the transistor (Q 1 ), during different time slots of a time period, to thereby produce a first base-emitter voltage (Vbe 1 ) and a second base-emitter voltage (Vbe 2 ), where I 1 =I 2 *M, and M is a known constant; an analog-to-digital converter (ADC) that digitizes analog signals representative of the magnitudes Vbe 1 and Vbe 2 ; and a digital calculator to produce a digital temperature reading (DTR) based on a digital value indicative of a difference between the magnitudes of Vbe 1 and Vbe 2 ; wherein the digital calculator determines the DTR using the equation DTR=K*Data/[K*Data/(2^N)+1], where K is a constant, Data is the digital value indicative of the difference between the magnitudes of Vbe 1 and Vbe 2 , and is N the number of bits of the digital value and the number of bits of resolution of the ADC, wherein N is an integer ≧2.