Digital temperature sensor, corresponding device and method

Abstract

First and second transistors produce a first signal indicating the voltage drop difference across the transistors and a second signal indicating the voltage drop across the second transistor. The first and second signals increase and decrease, respectively, with temperature sensed based on the first signal via a gain factor. An ADC coupled to the transistors produces a pulsed output bitstream with a duty cycle based on the first and second signals via the gain factor. A selection stage intermediate the transistors and the ADC alternates first and second cycles under control of the bitstream, to transfer to the ADC during the first and second cycles, first and second numbers of alternations of signal transfer phases, wherein the first and second signals, respectively, are transferred with alternate signs to the ADC. The gain factor is based on the ratio of the first to the second number of alternations.