Subject: Inquiry Regarding HDMI connection with power over Ethernet device.

Sakthivel B

Is this the same inquiry as this e2e thread, https://e2e.ti.com/support/isolation-group/isolation/f/isolation-forum/1292557/subject-inquiry-regarding-hdmi-isolation-chip-for-power-over-ethernet-poe-to-non-poe-device-integration? If this is the case, I will close this thread and someone will provide the response on the other thread.

Thanks

David

Hello David,

Consider this query separately, 

We need to know whether connecting the externally powered device with our POE device is possible or not?  Here we don't planned to use any Isolators other than TI regulators.

Thanks,

Sakthivel

Hi Sakthi,

Yes, your system architectire is possible from a PoE perspective. The injector will add DC power to ethernet lines which will then be used to connect to your PCB board. On your RJ45 you will have a data transformer where the center taps will be used to pull the DC power for PoE. From there, on your PCB design you will need a PoE powered device (PD) in order to recieve the load and convert the voltage to system desired voltage level.

How much power is needed here?

Regards,

Brandon

Hi Brandon,

Thanks for your support,

Our concern is to connect an external HDMI monitor with our system, which is powered by POE. We are thinking that if the two grounds (POE ground and external DC ground) are mixed, then a small potential difference may create and a current will flow in that may cause damage to the HDMI monitor or other devices connected to our carrier board. Could you please check and confirm if our understanding is correct or if it will not happen like the way we are assuming?

Does connecting externally powered devices (ie, HDMI monitor , Micro B USB, GPIO's in GPIO headers ) with POE powered device is advisable without isolation?

Our system required 20 Watts of power and we are about to use AT standard POE injector, 

Thanks,
Sakthivel