SN74LVC2G125: Displayport AUX channel buffer

Jim CHEN

Expert 4795 points

Part Number: SN74LVC2G125

Dear Team,

My customer is looking for the buffer or redriver that can drive AUX signal of Displayport.

Because they will use about 10 meter cable in their design.

So I have no idea if SN74LVC2GXX serial device is the correct solution for this application.

Please help to confirm that or provide another appropriate solution.

Thank you very much.

over 7 years ago

0 Emrys Maier over 7 years ago

TI__Guru* 96842 points

Hi Jim,
Do you know the operation frequency and characteristic impedance of the line? Operating voltage?

I know that the default AUX line speed is 1 Mbps which should be slow enough for this device to work, however there is a 'Fast AUX' mode that operates at 720 Mbps and is well beyond the capabilities of the SN74LVCxx series of devices.

At 10m, anything beyond about 3MHz will see transmission line characteristics playing a large role in signal integrity. The SN74LVCxx series of devices won't be able to drive enough current for a 50 ohm transmission line at 5V.

0 Jim CHEN over 7 years ago in reply to Emrys Maier

TI__Expert 4795 points

Thank you for your reply.
Therefore, if my customer only use default AUX line speed, they can choose SN74LVCxx series as the correct solution, am I right?

0 Jim CHEN over 7 years ago in reply to Jim CHEN

TI__Expert 4795 points

After confirmation, they don't need to support Fast AUX mode.

Below is the aux parameter:

Thanks.

0 Emrys Maier over 7 years ago in reply to Jim CHEN

TI__Guru* 96842 points

From the specs listed, it looks like this is a differential line (which makes sense). Unfortunately, logic devices are all single ended except the LVDS devices.

0 Michael J Schultis over 7 years ago in reply to Emrys Maier

TI__Mastermind 24885 points

Hello Jim,

Yes, for differential signaling, you may want to look under the following product tree:
www.ti.com/.../lvds-phy-less-than-800-mbps-products.page

Best,
Michael

Logic

Logic forum

SN74LVC2G125: Displayport AUX channel buffer