• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 45 subscribers
  • Views 406 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.

Application of the ADS131 for vibration monitoring

Hongki Jo1
Prodigy 65 points
Other Parts Discussed in Thread: ADS1274, ADS131E04

Hi, 

As Joachim recommended, now we are considering ADS131E04/E08 for our applications (vibration monitoring of low-frequency structures). I know ADS1274/1278 is  well suited for such application, but too high sampling rate (minimum 10kHz) and corresponding high power consumption are concerns for us. 

The ADS131E04/08 is basically suited for power monitoring. We just wonder if there is any concern in using it for vibration monitoring except relatively narrow flatband in frequency response. The input signals are all positive analog voltage (dynamic signal) with frequencies 1~200Hz.

  • 0
    TI__Mastermind 23275 points

    Hi Hongki (or is Jo your first name?),

    I don't see any real concerns in using the ADS131E04 for measuring those signals.
    As I commented in the other post, the only concern would be the attenuation of the SINC3 filter within the passband. Table 1 in the datasheet shows the -3dB frequencies for the different data rates. If you choose a high output data rate the -3dB frequency is 'far' away from your 200Hz signal. If you can live with a small amount of attenuation at 200Hz then all should be fine.

    If you really need a flat passpand response of the digital filter then you will have to implement some sort of compensation in the digital domain within your MCU. The filter response of the ADS131E04 is given in equations 4 and 5. That should give you an idea of how to compensate it.

    Another thing to watch out for with the SINC3 filter is that you don't get as much attenuation at frequencies above Nyquist as with the FIR filter of the ADS1274. So you need to watch out for aliasing effects in case your input signal has signal content above Nyquist.

    I also wanted to comment on the ADS1274. You can actually run the device with very low master clock frequencies. The output data rate and - probably more important for you - also the power consumption will scale with a lower clock frequency.
    You could for example use a 512kHz clock in low-speed mode to get an output data rate of 1kSPS. I can unfortunately not tell you by how much the power would reduce then.

    Regards,