Abstract: A circuit is provided. The circuit includes a control circuit, a voltage sensor coupled to the control circuit, an indicator signal coupled to the control circuit, and at least one current source. The control circuit, responsive to the voltage sensor, is configured to detect a first classification voltage within a classification voltage range defined by a lower classification voltage limit and upper classification voltage limit, detect, after detecting the first classification voltage, an indexing voltage outside of the classification voltage range, and detect a second classification voltage within the classification voltage range. The at least one current source provides a first and second predetermined classification current responsive to the first classification voltage and the second classification voltage, respectively.

Abstract: A circuit is provided. The circuit includes a control circuit, a voltage sensor coupled to the control circuit, and an indicator signal coupled to the control circuit. The control circuit, responsive to the voltage sensor, is configured to detect a first classification voltage within a classification voltage range defined by a lower classification voltage limit and upper classification voltage limit, detect, after detecting the first classification voltage, an indexing voltage outside of the classification voltage range, and detect, after detecting the indexing voltage, a second classification voltage within the classification voltage range. The control circuit is further configured to set the indicator signal to a first predetermined state indicating a power type based on the detected first classification voltage, indexing voltage and second classification voltage.

Abstract: A method of classification of power requirements in a power over Ethernet system, the method comprising: providing a first classification voltage for a first classification cycle time, the provided first classification voltage being within a classification voltage range defined by a lower classification voltage limit and upper classification voltage limit; measuring a first current flow responsive to the provided first classification voltage; subsequent to the first classification cycle time, providing a voltage outside of the classification voltage range for a classification indexing time; subsequent to the classification indexing time, providing a second classification voltage for a second classification cycle time, the provided second classification voltage being within the classification voltage range; measuring a second current flow responsive to the provided second classification voltage; determining a classification responsive to the measured first current flow and the measured second current flow; and