• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 33 subscribers
  • Views 144 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DS90UB954-Q1: lock pin noise interference

Henry Wang3
Genius 3365 points
Part Number: DS90UB954-Q1
Other Parts Discussed in Thread: DS90UB953-Q1, , ALLIGATOR

Hi Sir,

My customer is using the DS90UB954-Q1 board with the PoC circuit to provide the 12V/2A power to the DS90UB953-Q1 board with 4-ch LED driver circuit.
When the LED turn on, they found the 50Hz noise interference on the DS90UB954-Q1 lock pin and DS90UB953-Q1 clkout pin .
Could you please advise how to resolve this issue?

DS90UB954 lock pin noise interference.docx

  • 0
    TI__Guru 66840 points

    Hi Henry, 

    Can you measure/observe any noise on the actual power rails themselves?

    Also, for these measurements, is the oscilloscope probe getting grounded close to the pins? Sometimes if the probes long alligator clips are used noise can be coupled to the ground clip, and the noise not actually be real.

    The 50Hz is likely the LED PWM frequency. The LED driver could be injecting noise into the 953 board. If this is the case, then it will be the LED driver that needs debugged/modified with filtering, etc.

    Is there any loss of FPD-Link operation when the LED driver comes on? Loss of lock, parity errors, etc?

    Regards, 

    Logan