Capacitor coupled in parallel to a rectifying element of a rectifier in power-over-ethernet powered device to bypass noise from power line

A power-over-Ethernet (PoE) powered device (PD), comprising:

• a PoE interface configured to removably receive a connector of an ethernet cable to communicably connect the PD to a PoE power sourcing equipment (PSE), the PoE port comprising a first pair of electrical connectors and a second pair of electrical connectors;
• a first power line connected to the first pair of electrical connectors and a second power line connected to the second pair of electrical connectors such that differential signals applied by the PSE to the first and second pairs of electrical connectors apply a DC voltage between the first and second power lines;
• a PD chip having a first terminal and a second terminal;
• a diode bridge rectifier comprising:
• a first input connected to the first power line, a first output connected to the first terminal, and a first diode connected to allow current from the first input to the first output;
• and
• a second input connected to the second power line, a second output connected to the second terminal, and a second diode connected to allow current from the second input to the second output;
• a first bypassing capacitor connected in-parallel to the first diode between the first input and first output, wherein AC noise appearing on the first power line is bypassed around the first diode via the first bypassing capacitor;
• and
• a second bypassing capacitor connected in-parallel to the second diode between the second input and the second output, wherein AC noise appearing on the second power line is bypassed around the second diode via the second bypassing capacitor.

A method comprising:

• receiving AC noise at a first input of a rectifier of power-over-Ethernet (PoE) reception circuitry in a PoE powered device (PD), wherein the first input is connected to a first output of the rectifier via a first rectifying element and a first capacitor which are connected in parallel between the first input and the first output;
• bypassing the AC noise from the first input to the first output via the first capacitor;
• and
• directing the bypassed noise from the first output to a ground conductor via a second capacitor connected in series between the first output and the ground conductor.