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AD7492:reference

Hi!

I want to take the internal reference from the REFOUT pin AD7492. There is no typical connection diagram for it in AD7492 Datasheet. How can I use it in a system correctly?

  • Hi 150380jane,

       The AD7492 has a 2.5V internal reference that can be output in the REFOUT pin. The 2.5V internal reference is buffered and connected to the core 12bit SAR ADC. To stabilize the 2.5V internal reference, it is recommended to place a 100nF capacitor at the REFOUT pin of AD7492. Figure 15 of the AD7492 datasheet shows the typical circuit diagram of the AD7492.

    Regards,

    Jonathan

  • Hi, jcolao!

    In other words I can connect  this pin to a resistor with any impedance and  REFOUT doesn't drop. If it is not so why aren't there any other parameters, except reference voltage, in AD7492 Datasheet?

  • Hi 150380jane,

          Connecting a resistor on the REFOUT can affect the performance of the AD7492 and we cannot guarantee the specification when a circuit or a component is connected on the REFOUT pin other than the recommended capacitor.             Do you have plans connecting the REFOUT to another circuit? There are other ADCs when using the internal reference for  other circuit in the system, it is recommended to have an external buffer. May I know what system you are trying to build.

    Regards,

    Jonathan

  • Hi, jcolao!

          I just wanted to take part of the REFOUT. But according to Figure 1 and Figure 12 of the AD7492 datasheet  the core 12bit SAR ADC contains a capacitive DAC and I don't have a lot of ways to take the REFOUT. All I wanted to know how to take the REFOUT and the AD7492 have a good conversion result with it.

    Thanks a lot for your time and for your answer.

    Regards,

    Jane