Circuit for processing a signal of a measuring sensor

Abstract

The invention is directed to a circuit for processing a signal (UL) of a lambda probe having a probe signal terminal on which the signal (UL) is outputted and a probe ground terminal. The circuit includes a voltage source having a plus pole and having a minus pole connected to the probe ground terminal. A first network of passive components is connected between the plus pole and the probe signal terminal for dividing the voltage between the plus pole and the probe signal terminal in a pregiven ratio thereby providing a divided potential as a first analog signal. An analog-to-digital converter has an input and is connected to a chassis ground at a ground potential different than the ground potential at the probe ground terminal. A second network of passive components is connected to the plus pole for supplying a potential proportional to the potential on the plus pole as a second analog signal. The input of the converter is directly connected to the first network to receive the first analog signal and to the second network to receive the second analog signal thereby facilitating digital processing of the first and second analog signals in the converter.

Dependencies are inferred from the claim text.