Patent ID: 7863871

Claim:
An apparatus for monitoring for an alternating current (AC) power signature of a powered device (PD) from among a plurality of PDs in a Power Source Equipment (PSE) Controller, comprising: a charge pump configured to provide a first signal based upon a first clock; and a plurality of AC disconnect modules coupled to the charge pump, each of the plurality of AC disconnect modules being coupled to a corresponding PD from among the plurality of PDs, wherein each of the plurality of AC disconnect modules is configured to switch between the first signal and a second signal based upon a corresponding one of a plurality of second clocks to produce a corresponding one of a plurality of third signals, and to apply the corresponding one of the plurality of third signals to the corresponding PD, the plurality of third signals being configured such that only one of the plurality of third signals corresponds to the first signal at a given time; and a voltage measurement system configured to determine an impedance of the corresponding PD by measuring the corresponding one of the plurality of third signals, the impedance of the respective PD determining the AC power signature for the corresponding PD.