Patent ID: 9007071
Filing Date: 2015-04-14
Classification: H03K

Abstract:
1. An evaluator circuit, comprising: a first resistor configured to electrically couple to a first receiver coil of an inductive proximity sensor, wherein a first resistor value of the first resistor is determined based on a first tolerance of the first receiver coil; a second resistor configured to electrically couple to a second receiver coil of the inductive proximity sensor, wherein a second resistor value of the second resistor is determined based on a second tolerance of the second receiver coil, wherein the first resistor is configured to electrically couple to the second resistor at a node; a filter configured to generate a filtered differential signal by filtering noise from a differential signal between a first voltage signal associated with the first receiver coil and a second voltage signal associated with the second receiver coil, wherein the filter receives the differential signal via the node; an amplifier configured to generate an amplified differential signal by amplifying the filtered differential signal; and output circuitry configured to compare a change in the amplified differential signal with a first threshold and indicate a detected target when the change in the the filtered differential signal is above the first threshold.