• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 46 subscribers
  • Views 231 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.

ADS1605: external reference voltage

Thomas Wiepen
Prodigy 20 points
Part Number: ADS1605
Other Parts Discussed in Thread: REF5045

Hi Team,

I have a question on the use of an external reference voltage source for the ADS1605. 

How do you solve the requirement of three different voltages (4V, 2,5V, and 1V) on the VREF pins of the ADC. There is also the problem that 4V and 1V is not really common as a voltage reference. Working with three separate voltage references will also reduce the available space on the PCB that could lead to a problem later on.

Is there an example or suggestion for using an external voltage reference with this ADC?

Thanks for your answer.

Best regards,

Thomas 

  • 0
    TI__Mastermind 40860 points

    Hello Thomas,

    First, welcome to the TI E2E Community.

    If using an external reference, please refer to Firgure 14 in the datasheet for the reference buffer.  You can then generate the 3 voltages (4V, 2.5V, 1V) using a single low noise reference, such as REF5045, and precision resistor networks.  This is how we generated the voltages when testing the ADS1605 at TI.

    Below is an example circuit with the different resistor values needed when using a 4.5V reference.

    Regards,
    Keith Nicholas
    Precision ADC Applications

  • 0 in reply to Keith Nicholas
    Prodigy 20 points

    Hello Keith, 

    thank you for your answer which is much easier than I expected. =)

    Best regards,

    Thomas