Inductive position sensing with single channel interface to multiple resonant sensors

摘要

An inductive sensing system includes multiple resonant sensors interfaced to an inductance-to-digital conversion (IDC) unit through a single channel interface. IDC establishes an IDC control loop that incorporates resonant sensors as loop filters. The IDC control loop drives resonant sensors to a system resonance state in which each resonant sensor is driven to a resonant frequency state. Each resonant sensor is configured for a nominal resonant frequency state that differentiates it from the other resonant sensors. IDC senses changes in system resonance state representative of target-sensing conditions, and responds by driving a target-sensing system resonance state. IDC converts IDC loop (resonance) control signals resulting from a target-sensing condition into sensor data as representing the corresponding target-sensing resonant frequency state as an indication of target position (proximity or range) relative to a target-sensing resonant sensor. The sensor data can be provided to a data processor for proximity/range processing.