• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 46 subscribers
  • Views 150 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.

Original question:

ADC128S102EVM pin description

ADC128S102EVM: 5V only configuration

Jonathan Donovan1
Prodigy 40 points
Part Number: ADC128S102EVM

The ADC128S102EVM pin description thread had an answer that stated: "If you have VA set to 5V, you can use IN4 and IN5 with inputs up to 5V. IN0 - IN3 and IN6 are limited to 3.3V because of the op amp that is in the signal path, which is powered by a 3.3V supply. Putting 5V on IN0 - IN3 and IN6 will damage the op amp. If you want to use these inputs with a 5V input signal, you will need to modify the board."

Can you source 5V into the "3.3V rail", such that all devices receive 5V power? It looks like all of the components can handle 5V. You would just need to make sure VA is jumpered and receives 5V via VA-EXT. Are there other modifications that would be needed to allow you to input 5V signals into the ADC? 

Thanks.

  • 0
    TI__Mastermind 24940 points

    Hello,

    the op amp power rail is not connected to the VA of 5v rail. the 3.3V rail powering the op amp and the ADC VD rail are powered from JA-pin1 header.

    If the same power supply is connected to VA-EXT and JA-1 then the EVM should work fine

    Note, that this means the EVM cannot be connected to the MSP430 launchpad, as the power rails are provided by the launchpad.

    you cannot connect the EVM to the launchpad, and supply a separate power supply to the 3.3V rail.

    Regards

    Cynthia