Agere Systems Inc.

Luis De La Torre

Gary D Polhemus

Fadi Saibi

Patrick J Quirk

Matthew Blaha

Alan Leon Ellis

Gary D Polhemhus

In one embodiment, a powered device (PD) () has a PHY module () and a media access controller () (MAC), the PD () adapted to connect to power sourcing equipment (PSE) via a cable, () where the PD () is adapted to communicate with and receive power from the PSE via the cable, in accordance with the Power-over-Ethernet (PoE) standard. The PD () extracts () from the cable () a DC signal used to power the PD without using a transformer. Capacitors () located in the signal paths between the MAC () and the cable () support electrical isolation of the MAC ().

Transformerless power over ethernet system

Disclosed is a current mode switched power supply. The current mode switched power supply includes a switching element and a power stage coupled to the switching element and configured to provide, in response to the switching of the switching element, an output voltage and a feedback voltage related to the output voltage. The current mode switched power supply also includes a digital control circuit connected to the switching element to digitally control the switching of the switching element.

Digitally controlled current-mode switched power supply

One embodiment monitors a line-side electrical current provided by a power sourcing equipment (PSE) port to a powered device (PD), the PSE port having a power-isolation transformer with a primary coil on an isolated side and a secondary coil on a line side. A switching signal having a switching period and a duty cycle is applied to the primary coil of the power-isolation transformer. A value is determined for an electrical current on the isolated side of the power-isolation transformer, conversion is performed between a line-side electrical current value Iand a corresponding isolated-side peak-current value I, and the line-side electrical current is indirectly monitored based on the determined isolated-side current value.

Isolated switched maintain power signature (MPS) and fault monitoring for power over Ethernet

In accordance with the invention, feed forward compensation of jitter induced by power supply noise is incorporated into the negative feedback control loop of a timing synchronization circuit, such as a phase locked loop or delay locked loop. More particularly, the dependence of the circuitry in the negative feedback loop, such as the delay elements in a DLL or the oscillator in a PLL, to fluctuations in the power supply are counteracted by introducing into the feedback loop a signal component that is a function of the supply voltage and that will have the opposite effect from any direct fluctuations in the power supply voltage.

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Daganzo de Arriba, Spain

Luis De La Torre