SN74CB3Q3245: USB3320 USB Phy isolation,

Hello Kenny,

So when you are referring to isolating the data and control lines I assume you are saying the switch will be powered but the signal paths will be disabled to block the 60MHz(1.8V) signal.

In this case we will have to look at multiplexers with high off isolation in there datasheets.

The SN74CB3Q3245 device can be a good option, however there is no off isolation data in the datasheet, but off isolation for TI switches and multiplexers are better in systems with small load impedances.

Another good solution would be using a multiplexer with good off isolation in the data sheet. The TMUX136 would be this option but would likely require a multichip solution.

All this being said completely  blocking a 60MHz signal  will be difficult to do with a mux/switch.

Is there a acceptable  amount of voltage you are  ok with having on the output of the mux/switch  when trying to block the 60MHz signal?

Please let me know what you think and I am happy to help.

Regards,

Kameron

Hi Kameron, thanks for the quick response.

The isolation I need is to prevent parasitic power, so the USB transceiver can be powered down and disconnected from the bus, completely isolating it. So when powered on the SN74CB3Q3245 would be enabled and connecting transceiver to SoM, when powered down it would be high impedance and isolated from the SoM. Not too worried about completely blocking AC signals. 

Think that sound like a sensible solution?  thanks for the support.