• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 47 subscribers
  • Views 324 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.

INA190: REF current

Alexander Yudin1
Prodigy 10 points
Part Number: INA190
Other Parts Discussed in Thread: ADS114S08

Hi community!

In my application i need to use INA190 with Vref =Vs/2 (Vs=5V, Vref=2.5V).

Selected ADC, ADS114S08, has internal reference source = 2,5V, but it has limited current capabilities.

I can't find any REF pin specification in INA190 datasheet.

How much current REF pin consume and should I place additional buffer between ADS REFOUT and INA190 REF?

  • 0
    TI__Mastermind 32395 points

    Hello Alexander,

    Welcome to the TI E2E forum.

    The REF pin is connected to the resistor coming off the non-inverting terminal of the INA190's output stage differential amplifier. So it is a high-impedance input and will not require much current at all. You can refer to this document (below), which measures all of the currents going into and out of the INA190 for many configurations. Overall, at mid-supply reference (Vs/2), the REF currents are less than 1uA and should not be much more than that. Maybe a few microamps max for measuring full-scale Vsense values. This looks to be well within the output current capabilities of your selected ADC's reference voltage source.

    http://www.ti.com/lit/an/sboa180a/sboa180a.pdf

    Hope this helps.

    Sincerely,

    Peter