Hello E2E community:
I'm looking into using something like the SN74CBTLV3383 Bus-Exchange switch to switch 10/100/1000BASE-T signals between two ports. I found the part on the TI website and it was listed under TI Home > Applications > Ethernet Switch.
Are there any application notes or an example circuit showing this in use for Ethernet? The datasheet is pretty generic on the applications.
The Ethernet application that I’m inquiring about requires the following connections would look something like the attached diagram.
There are two Ethernet ports coming from the Ethernet switch on the left hand side of the diagram. There are two modes that we would need to operate depending on where this card is plugged into the backplane.
- Mode 1: Port 1 and port 2 goes directly through the SN74CBTLV3383 to CH1 and CH2 connections, respectively on the backplane. In this case, Port 1 and Port 2 would operate as 1GbE as shown in the blue straight through lines in the diagram.
- Mode 2: Port 1 and port two are set into 10/100 mode. Pairs A&B and pairs C&D are bifurcated to become independent ports. Essentially, we have “four” ports – port 1a (Pairs A&B), port 1b (pairs C&D), port 2a (pairs A&B) and port 2b (pairs C&D). Ports 1B and 2A would cross each other as shown in the orange lines in the diagram. Ports 1B and 2B would remain a straight through connection.
The SN74CBTLV3383 has a series resistance of ~6ohms. We intend on adding ~6ohm resistors on to the “non-exchanged” lines to compensate for the series resistance of the “exchanged” lines.
Is this a sane application for the SN74CBTLV3383? If not, can you recommend a different part that would meet the requirements?
Regards,
Thomas
