PMP20859: Behavior Questions

Allan Fan

Part Number: PMP20859
Other Parts Discussed in Thread: LM5020

Hi expert,

May I learn with you how does the circuit work to turn off POE2 to let it as standby mode when both POE1 and POE2 are connected?

Thanks,

Allan

over 1 year ago

0 Diang Xing over 1 year ago

TI__Mastermind 32021 points

Hi Allan,

When the circuit starts work with both PoE1 & PoE2 connected, a correct Vout is presented. Q9 will be turned off and SS pin can be pulled high.

At that time, when you turn off PoE2 the LM5020 will continuously work to keep a correct Vout.

Best regards,

Diang

0 David Strasser over 1 year ago in reply to Diang Xing

TI__Intellectual 2530 points

Allan,

There is no priority for the PoE inputs with this design. The port with the higher voltage will supply the power. If the voltage on each port is close to being the same, there may be some sharing of power.

Thanks,

David

Simulation, hardware & system design tools

Simulation, hardware & system design tools forum

PMP20859: Behavior Questions