DS160PR822: Unused RX and TX pins

Renan Santos Adriano

Part Number: DS160PR822

Hello Team,

Can you share with us the suggested termination for unused RX and TX pins of DS160PR822? Is it okay to keep the unused RX and TX floating or terminate them with a resistor to GND?

Regards,

Renan

over 3 years ago

0 David Creger over 3 years ago

TI__Mastermind 27212 points

Hi Renan,

It likely will not make a huge difference, but as good practice, we recommend terminating the unused RX and TX pins with a 50 ohm resistor to ground. You should also have a decoupling capacitor the same as the other lanes. If you are not using all of channels 4-7, then pull PD1 pin high to turn them off.

Thanks,

David

0 Renan Santos Adriano over 3 years ago in reply to David Creger

TI__Mastermind 22450 points

Hello David,

Thank you for this response.

You are stating tying RX to GND, TX to GND, in addition to the .22nF series cap? So GND to RES to CAP to RX input? Will a 100ohm works also? Will the TX side be TX output to CAP to RES to GND?

Regards,

Renan

+1 David Creger over 3 years ago in reply to Renan Santos Adriano

TI__Mastermind 27212 points

Hi Renan,

You are correct. GND to RES to CAP to RX input. TX output to CAP to RES to GND.

Please use 50 ohm resistors. This is the termination that PCIe signals use.

Thanks,

David

Interface

Interface forum

DS160PR822: Unused RX and TX pins