HD3SS6126: HD3SS6126 Chaining

Hi Jeevan,

HD3SS6126 is a passive mux and can be daisy chained to fit your needed. We do not have a reference design here. Could you provide a block diagram of your system and I can provide further comment. In general when cascading passive muxes you may need a redriver to help recover the signal. I can also give comments on placement for redriver.

Hi,

Please see the diagram below.

I was hoping to make one board to be bidirectional so it can be used as a 1:4 or a 4:1 mux. I think if the redriver is placed between Mux 1 and Mux 2 as well between Mux 1 and Mux 3, I should be able to use this as a bidirectional board. Hopefully your input can shed some more light on this.

Thanks a ton!

Jeevan

Hi Jeevan,

From your block diagram may I suggest looking into a USB Hub like TUSB8041A? Using this device would achieve a similar functionality but in this case all 4 USB deivces could be used at once and no additional muxes are needed. Using a USB Hub can also eliminate the need for USB redrivers as well. Using this device the USB Host would be restricted to one side of the board and USB devices to the other.

If you would like the Host to be placed anywhere the I would place redrivers on in between the muxes but closest to the USB connectors? What are the expected trace lengths for this design?

Hi Malik,

I don't think I explained my use case properly as its non typical. I'm looking on making a USB mux that can fulfill two purposes, ideally in the same board but I can spin 2 boards if needed. The first usage is to switch 4 hosts between a single USB hub. This will allow me to select whichever host I needed. The second usage is to switch between 4 different USB devices that will connect to the host that was selected. I don't want to use a USB hub since I may have high bandwidth devices such as 1080p 60fps uncompressed video stream cameras. Having multiple of these connected to the same system has caused issues in the past. This is why I only want one of them connected at a time. A block diagram of the whole setup is below.

I was hoping to have a single bidirectional Mux that could serve as both of the Muxes in the setup above. I'm not sure if this is possible but hopefully with your experience, we can determine this. If it's easier, we can setup a quick 5 min call to discuss this.

Let me know if anything is unclear or if you have any questions for me.

Thanks a ton!

Jeevan 

The image didn't attach above so here it is

Hi Jeevan,

I understand now, HD3SS6126 can be used in a bi-directional manner as well. My only concern here would be the signal integrity at the "4" end of the mux. There are good options for redrivers here. TUSB522P would be a good place to start. 

Hi Malik,

Would you place the redriver between Mux 1 and Mux 2 as well as between Mux 1 and Mux 3? Also, is there any app notes/white papers for the usage of USB re-drivers?

Thanks,

Jeevan