ADS8688: ADS8688 is locking

Furkan Usu

Part Number: ADS8688

hi, we are using ads8688 in our project.Sometimes we are reading same and meanless data all of channel after power up,ADS8688 is responding other commend correctly.When we examine it with oscilloscope, we see that this value is "Data from sample n" that comes after writing "Man Ch N".This situation does not get better without power on/off.When we delay AVDD, we do not encounter a situation like locking. What could be the reason?

8182.ADS8688.pdf

over 1 year ago

0 Tom Hendrick over 1 year ago

TI__Guru**** 168445 points

Hi Furkan,

Welcome to our e2e forum! This sounds like power/grounding issue to me. When you say you 'delay AVDD, we do not encounter a situation' - can you describe or show screen captures of this delay? Have you verified that you are not exceeding any of the conditions specified in the Absolute Maximum Ratings table on page 6, section 7.1? I can't tell what you are doing ecactly with the Photo MOS devices and how AIN_nGND might be pulled relative to the chip ground. You can also try replacing L5 with a zero ohm resistor and see if that helps.