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Original question:

DS90UB947-Q1: Query for power up requirements

DS90UB947-Q1: Power-Up Requirements for VDD11

Youhei Miyaoka
Expert 6085 points

Part Number: DS90UB947-Q1

Tool/software:

Hi team,

My customer have additional questions about Power-Up Requirements from previous thread.

1. You mentioned with below comment;

> t2 begins whenever the OLDI CLK has stabilized (with +/- 0.5% variation).

How to judge OLDI CLK has stabilized?

2. Seeing from requirement, it seems VDD11 should start up faster than 1.5ms. The most of Primary DCDC can not meet the requirement.

What kind of risk hidden if they cannot fulfill the requirement? They need to consider Secondary DCDC with faster start-up than 1.5ms. Is this correct?

Regards,

Youhei MIYAOKA

  • 0
    TI__Mastermind 37390 points

    Hello Youhei,

    Youhei Miyaoka said:
    How to judge OLDI CLK has stabilized?

    Just make sure your OLDI source is sending stable CLK within +/- 0.5% variation. You can check that on the scope on your SoC output to ensure that you allow enough delay for the source to send stable clock. Or can consult SoC vendor about this information. 

    Youhei Miyaoka said:
    What kind of risk hidden if they cannot fulfill the requirement? They need to consider Secondary DCDC with faster start-up than 1.5ms. Is this correct?

    Any violation of power sequence could end up with a flickering screen or black screen, etc. To avoid video artifacts, please ensure you follow the power sequence provided in the datasheet.

    Regards,
    Fadi A.