• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 47 subscribers
  • Views 364 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.

Original question:

ADS1258: questions on clock of ADS1258

ADS1258-EP: ADS1258-EP

Ahamd Moghaddam
Prodigy 30 points

Part Number: ADS1258-EP
Other Parts Discussed in Thread: ADS1258

Hi

I have a question on external clock source requirement for  ads1258-EP.

Does it have to be  be 16MHz? or the external source can be any other frequency for example 12.5 MHz? what would be the impact of having a non 16MHZ ?

Thanks in advance for your response

  • 0
    TI__Guru 58971 points

    Hi Ahamd,

    Per the ADS1258 datasheet, the clock frequency (fCLK) can vary from 0.1 MHz to 16 MHz. Please also ensure that the duty cycle requirements are met.

    The consequence of changing fCLK is that the data rate scales accordingly. See table 5 for the nominal data rates at 16 MHz. For example, if you set DRATE[1:0] = 11b, the data rate would be 125 kSPS when fCLK = 16 MHz and 62.5 kSPS when fCLK = 8 MHz.

    Also, the effective input impedance is a function of fCLK, per the description in the "ADC Inputs" section on page 16.

    -Bryan

  • 0 in reply to Bryan Lizon86
    Prodigy 30 points

    great. thanks for the prompt technical insight Bryan