• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 45 subscribers
  • Views 429 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.

ADS1222 REF input

Hiroshi Sato
Expert 2590 points
Other Parts Discussed in Thread: ADS1222

Hello,

How much current required for VREF pin ?

Our customer  now evaluating  ADS1222 with Vdd=3.2V and VREFP=1.6V that is made by 1/2Vdd with resistor divider and VREFN=GND.

They want to make less power consumption, it is better with the bigger resistor value.  

Thanks and best regards,

Hiro

  • 0
    TI__Guru* 98025 points
    Hiroshi-san,


    The reference input is modeled as an input resistance. From the datasheet, it can be found in the specification table and on page ten in the description of the reference inputs.

    However, the reference inputs are switched capacitor circuit that sample the applied voltage. It is important that they be driven from a low impedance source or the capacitor will not be fully charged. If the reference is not correctly sampled, this may result in gain error.

    Generally we use a low output impedance reference so that the reference sampling is correct.


    Joseph Wu