Patent ID: 8319500

Claim:
A proximity sensor, comprising: a variable gain oscillator adapted to receive electrical energy, the variable gain oscillator including a sensor coil and having a gain that varies with proximity of a target to the sensor coil, the variable gain oscillator coupled to receive a feedback signal and configured, in response to the feedback signal, to (i) generate an oscillating electrical signal having a substantially constant amplitude magnitude and (ii) generate an energy signal representative of the electrical energy received by the variable gain oscillator; a feedback circuit coupled to receive the oscillating electrical signal and configured, in response thereto, to supply the feedback signal; a proximity determination circuit coupled to receive the energy signal and configured, in response thereto, to supply a proximity signal representative of target proximity to the sensor coil; and a health monitor circuit coupled to receive the oscillating electrical signal and configured, in response thereto, to supply a health status signal representative of proximity sensor health.