• State TI Thinks Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 33 subscribers
  • Views 697 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.

DS90UB953-Q1: Does DS90UB953-Q1 have internal oscillator block that generates 400kHz?

K.Yaita
Guru 29720 points
Part Number: DS90UB953-Q1
Other Parts Discussed in Thread: DS90UB954-Q1,

Hi Team,

My customer is evaluating DS90UB953-Q1 with DS90UB954-Q1 and facing EMI problem in his system.
He said period of the EMI noise is about 400kHz and suspects the cause is attributed to these devices.

Does DS90UB953-Q1 have internal oscillator block that generates 400kHz?
My customer wants to know it for finding a way to reduce periodical 400kHz noise in his system

Best Regards,
Yaita / Japan disty

  • 0
    Guru 29720 points

    May I have your comments?
    Your support would be appreciated.

    Best Regards,
    Yaita

  • 0 in reply to K.Yaita
    TI__Intellectual 2010 points
    Hi Yaita,

    I don't think there's 400kHz internal oscillator inside. Because the DS90UB954 and DS90UB934 are designed to operate based on a 25MHz reference clock. This oscillator not only provides CSI-2 output frequency, but also for internal timers including I2C timers, FrameSync generation, Video Skew/Timestamp resolution, Back Channel Frequency, PLL timers, and Pattern Generator timings.

    Like I2C timing you mentioned, it is based on the 26.25MHz REFCLK signal. Min_delay = 38.1 ns × (SCL_HIGH_TIME + 5) (see 953 datasheet P22), where SCL_HIGH_TIME is a decimal numeral controlled by the register. There's no 400kHz oscillator.

    Best regards,
    Cera