Patent ID: 7038447

Claim:
A sensor circuit comprising, a sensor element; a current source for supplying an operating current for the sensor element; an amplifier circuit for amplifying a sensor voltage produced by the sensor element when applying the operating current, the amplifier circuit comprising a resistor influencing the amplification of it, wherein the resistor of the amplifier circuit and the sensor element are of the same type and formed by the same production technology so that variations, due to the production technology, of the sensor sensitivity of the sensor element are counteracted by an amplification factor of the amplifier circuit changing in the opposite way, wherein the current source has a band gap circuit including a first and a second bias resistor for providing a first and a second bias current, and wherein the amplifier circuit has reverse feedback resistors, wherein the bias resistors and the reverse feedback resistors are of the same type and of a type different from the sensor element.