ADS8681EVM-PDK: how do i check the signal phase data from the ADS8681EVM-PDK software

Hi pragash,

Are you talking to change the phase and priority of SPI in the GUI software? Please clarify it, thanks.

Best regards,

Dale

Hi Dale Li,

I am a colleague of Mr. Pragash. We need to get the phase of the signal we are receiveing through the GUI. I wanted to ask is there a way to get the phase of the signal directly through the GUI?

Best regards,

Nayan

Hi pragash,

ADS8681EVM GUI does not support this feature because the GUI is only used to support basic functionality of ADC including spectral analysis, histogram analysis and so on. If you have to use ADS8681, you can get the phase of your signal by doing post-processing (FFT or other method) based on the raw data which are captured from the ADC.

If other ADC can be considered, ADS8686S is a good option which has a similar input structure as ADS8681. ADS8686S is a 8-ch, 16-bit, dual simultaneous-sampling ADC. The ADS8686SEVM GUI has integrated Phase Analysis feature which calculate and directly show the phase difference of signal on each channel comparing with a signal on the reference channel. You can test it on ADS8686SEVM and see the result in the GUI. See the screenshot of the GUI and the details in the application note below.

Reducing Phase Delay by Averaging on ADS8686S with Burst Sequencer Mode

Regards,

Dale

Dear Dale Li thank you for the valuable input and guide. two other problem we face with ADS8681EVM GUI are:
1) it only captures 1048576 samples. it doesn't have continuous data capturing capability.
2) it doesn't have direct interface to matlab. only limited amount of data can be saved and need to be manually exported to matlab.
does these two problems have solution with GUI of ADS8686SEVM?

Will it be possible to provide us an API so that we can collect reading continuously using matlab?

Dear Dale Li,

i have another question, i saw ADS8686SEVM  have dual simultaneous ADC. i believe this dual simultaneous ADC is for differential mode operation. my question is, does the phase analysis only available for differential mode? i'm asking this because we need single ended mode only. 

Hi pragash,

The GUI is only designed to support and show basic functionality of ADC. Unfortunately, the details about the GUI can not be shared. The best solution for you is to design your own circuit board with your controller.

Regards,

Dale

Hi pragash,

To answer your 2nd question, the ADS8686S only supports single-ended input and it does not support differential input. The dual simultaneous-sampling is designed for some customers who need at least two simultaneous-sampling channels to minimize the delay from ADC device.

Regards,

Dale

so you are saying that the phase analysis has nothing to do with differential input. ok got it.

Hi pragash,

Correct, ADS8686S only supports single-ended input signal as I said. The negative input pin on each channel should be directly shorted to the ground or through a resistor in the balanced-input RC filter.

Regards,

Dale