SN65LVPE512: Terminating unused channel

Antenna_Head

Genius 11605 points

Part Number: SN65LVPE512
Other Parts Discussed in Thread: TUSB501

Team-

We have an application where only one side of the SN65LVPE512 is needed, RX1 => TX1.

What is the appropriate way to terminate RX2N:P and TX2N:P so that the device doesn't shut down?

Thanks, Best, S. Dunbar, AFA Colorado

over 7 years ago

0 Moises Garcia over 7 years ago

TI__Mastermind 23815 points

Hi Antennahead,

We no longer recommend LVPE512, the customer can try TUSB501 this si a single channel redriver.
If the customer wants to stick with LVPE512 and just use one channel they can set termination resistors on Tx pin of unused channel, place 50 ohms resistors to GND on each signal of Tx pair.

Regards

0 Antenna_Head over 7 years ago in reply to Moises Garcia

TI__Genius 11605 points

I understand; This is on an existing board and we need to get this to work.

We will recommend another device for the next revision.

To clarify, the unused channel is RX2=>TX2. These 50 Ohm resistors should go on pins 11:12 (RGE package)?

0 Moises Garcia over 7 years ago in reply to Antenna_Head

TI__Mastermind 23815 points

Hi Antennahead,

Yes, place one 50 ohm pull-down on pin 11 and one 50 ohm pulldown on pin 12 of LVPE512RGE.

Regards

0 Antenna_Head over 7 years ago in reply to Moises Garcia

TI__Genius 11605 points

We found experimentally that by placing a 50 Ohm resistor only on pin 12 was sufficient to keep the device running.

Do you see any issue with this on these proto-types or must be terminate both pins 11 and 12?

Thanks, Best, Steve

0 Moises Garcia over 7 years ago in reply to Antenna_Head

TI__Mastermind 23815 points

Hi Antennahead,

Placing only one pull-down is not a robust solution, it may have noise problems.
Please populate both pull-downs in pins 11 and 12.

Regards

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SN65LVPE512: Terminating unused channel