• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 45 subscribers
  • Views 147 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.

ADS112C04: high frequency is superimposed on DC

ttd
Mastermind 8580 points
Part Number: ADS112C04

Dear Technical Support Team,

How does the ADS112C04 behave when DC + high frequency is applied to the analog input?

If the following Peak to Peak high frequency is superimposed on DC, is there a bias voltage inside the IC or is there any effect?

The expected pattern is six.

13MHz ⇒　①1mp-p ②100mVp-p, ③1Vp-p
400kHz ⇒　④1mp-p　⑤100mVp-p　⑥1Vp-p

Best Regards,

ttd

  • 0
    TI__Guru** 113765 points

    Hi ttd,

    Usually when I see this type of question asked is when a customer wants to directly connect an input to the ADC without using a filter in front of the ADC input.  It is thought that the digital low-pass filter will remove the high frequency content.  However, aliasing is a primary consideration.  Aliased signals are not removed by the digital filter as the aliased signal resides within the passband.  Generally an appropriate antialiasing RC filter in front of the ADC input will take care of any issues.  See the section 9.1.4 on Analog Input Filtering in the ADS112C04 datasheet.

    As to the specific affects, it will depend on the data rate and the input signal level.  When characterizing the device there is always an antialiasing filter in front so we do not have specific data for these types of cases as it is not within recommended operation of the device.

    Best regards,

    Bob B