Patent ID: 9638584
Date: 2017-05-02
CPC Classifications: G01K,H01L

Claim:
1. A differential temperature sensing circuit comprising: a first junction device having a p-n junction that draws current from a first node as a function of temperature; a scaling resistor coupled between the first node and a first sense node; a first current source that generates a first current from a power supply to the first sense node in response to a bias voltage; a second junction device having a p-n junction that draws current from a second node as a function of temperature; a second current source that generates a second current from the power supply to the second node in response to the bias voltage; a difference amplifier that compares voltages of the first sense node and the second node to generate the bias voltage as a function of a voltage difference between the first sense node and the second node; a differential amplifier having a first differential input, a second differential input, a first differential output, and a second differential output; a third current source that generates a third current from the power supply in response to the bias voltage; a first current sink that sinks the third current to a ground supply to generate a mirror voltage; a second current sink that generates a first mirror current to the ground supply in response to the mirror voltage, the first mirror current being applied to the second differential input of the differential amplifier; a first multiplier resistor coupled between the first differential input of the differential amplifier and the second differential output of the differential amplifier; a second multiplier resistor coupled between the second differential input of the differential amplifier and the first differential output of the differential amplifier; and a fourth current source that generates a fourth current from the power supply in response to the bias voltage, the fourth current being applied to the first differential input of the differential amplifier.