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DS90UB948-Q1: Schematic review

Kygo Cheng
Expert 6830 points
Part Number: DS90UB948-Q1

Hi Team,

There is a good new that we DIN DS90UB948-Q1

And there have one thing need your support!
Please help check this SCH, THX

At present, the PASS and LOCK lights of UB948 power transmission test are off (connect to UB941)
The circuit is shown in the figure. The currently measured PDB pin is 3.3V.
Does the UB948 SCH need to be adjusted?

The current measurement C6=0V & C7=C34=2.5V! There seems to be a problem with UB948 now

RBD00703400TA1-SCH.PDF

  • 0
    TI__Guru** 108290 points

    Hello Kygo,

    I will review this schematic and provide my feedback by Dec, 3.

  • 0 in reply to Hamzeh Jaradat
    TI__Expert 6830 points

    Hi 

    Thank you for your help

  • 0 in reply to Kygo Cheng
    TI__Guru** 108290 points

    Hello Kygo,

    Here is my review feedback:

    - LVDS output Pins: The 100 ohm Termination resistor mentioned in the d/s is only required across the input terminal pair of the receiver. This termination resistor, which should be placed as close to the receiver as possible, is needed to generate the differential voltage across the receiver inputs, and to match the transmission line impedance to reduce reflections. Some LVDS receivers have integrated 100ohm termination resistors. An external termination should not be used when using such a receiver.

    - RIN1 +/-: Must be left as No Connect. Do not connect to an external pullup or pulldown.
    - To get the correct number/ values and connections for Decoupling caps, please refer to the d/s figure 8-2 "Typical Connection Diagram (STP)".