• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 46 subscribers
  • Views 638 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

ADS4249 PSRR

Guy Vaisman
Prodigy 30 points
Other Parts Discussed in Thread: ADS4249

Hello,

I have a question regarding the ADS4249 PSSR spec.

In the datasheet the PSRR is provided for an input signal of 10MHz. Should i expect different performence for input frequencies of ~200MHz?
Secondly, there in mentioning of PSRR performence for the DRVDD supply. Could you provide some data on this ?

Thanks in advance,

Guy.

  • 0
    TI__Guru* 91947 points

    Guy,

    I am checking with our design team regarding this.

    Regards,

    Jim

  • 0 in reply to jim s
    TI__Guru* 91947 points

    Guy,

    1. Ripple on analog power supply (or unclean supply) degrades the clock jitter. So you may see more degradation in ADC’s SNR at 200MHz than at 10MHz input frequency.

      So, if you band of interest is located at 200MHz or so, and you are worried about SNR degradation, keep the supply clean and free of ripples (try limiting it within +/-5mV).

    2. DRVDD is digital supply voltage. There is no direct way for a ripple on DRVDD supply to impact analog performance. So you may choose to use a switcher for this supply while choosing LDO for AVDD.

    Regards,

    Jim

  • 0 in reply to jim s
    Prodigy 30 points
    Hi Jim,
    Thanks for your answer.
    Guy.