DS90UB948-Q1: What is the configuration of the unused RIN pin

Zirui Su

Part Number: DS90UB948-Q1

Hi team,

I would like to need your suggestions that what should customer do with unused pins at the input of 948 FPD LINK(like the 1 and 3 pin in picture below)? Is 10K ohm grounded? Or is it grounded with a 10NF capacitor and a 50 ohm resistor?

over 3 years ago

0 Casey McCrea over 3 years ago

TI__Guru** 103215 points

Hello Zirui,

Are you asking for the connection of the pins of the HSD connector, or the RIN pins of the 948 device? For the 948 device, you should leave unused RIN channels as NC. For the connector you can either ground them (directly or with a pulldown resistor - either is fine) or leave them NC.

Best Regards,

Casey

0 Zirui Su over 3 years ago in reply to Casey McCrea

TI__Expert 5340 points

Hi Casey,

I just mean the 948 RIN pin. So it is not needed to add cap or resistor at these unused RIN pins right?

0 Casey McCrea over 3 years ago in reply to Zirui Su

TI__Guru** 103215 points

Hello Zirui,

Since those pins don't connect to 94x, we don't have any requirement. That would be a general system level decision from the customer

Best Regards,

Casey

0 Zirui Su over 3 years ago in reply to Casey McCrea

TI__Expert 5340 points

Hi Casey

Thanks for your reply, since customer saw in the 948 datasheet unused RIN0 add cap+50 ohms so we would like to know whether we do not use the R C is ok.

0 Casey McCrea over 3 years ago in reply to Zirui Su

TI__Guru** 103215 points

Hello Zirui,

The 948 datasheet is showing two different configurations. STP or Coax. In Coax mode the RIN- channel is not connected to the HSD port and then the RIN connection to the 948 is an RC combo of 47nF + 50ohm. But we don't mandate what needs to be done with the unused pins of the HSD connector itself

Best Regards,

Casey

Interface

Interface forum

DS90UB948-Q1: What is the configuration of the unused RIN pin