HD3SS3220: About high-speed signals on the TYPE-C side

arinori waki

Part Number: HD3SS3220

The HD3SS3220 evaluation board schematic shows
RX2P/RX2N and CRX1P/CRX1N are connected to the Type-C side of the TX2p/TX2n and TX1p/TX1p pins, and the receive signal appears to be connected to the transmit port.
However, the datasheet shows a configuration diagram with TX2P/TX2N and TX1P/TX1N connected to the TX2p/TX2n and TX1p/TX1p pins, which is correct?
Is either one OK?

7 months ago

0 David (ASIC) Liu 7 months ago

TI__Guru**** 150185 points

Hi,

Yes, the HD3SS3220 is a passive MUX, so it is possible to swap its TX & RX pins, you only have to care about the appropriate routing direction between the HOST and the connector.

Thanks

David

+1 Shane Hauser 7 months ago

TI__Genius 14775 points

Hi Arinori,

Either of these configurations could work so long as you are matching the input of the MUX to the output. In the EVM, the RX signals use the TX pins on the 3220.

This is ok because the MUX doesn't care which signal passes through either TX or RX, it will connect TX to TX1 or 2 and RX to RX1 or 2.

In the Datasheet, the RX signals use the RX pins on the 3220.

This is also ok, since the RX input is connected to SSRX on the USB host.

Best,

Shane

0 arinori waki 7 months ago

Prodigy 120 points

thank you.
I understand very well.

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HD3SS3220: About high-speed signals on the TYPE-C side