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ADCMXL3021_data rate

Category: Hardware
Product Number: ADCMXL3021

Hello

Could you teach me how to calculate the output data rate of FFT data of  ADCMXL3021   (capture duration) ?

I refer to below user guide and EZ Q&A.

https://wiki.analog.com/_media/resources/eval/user-guides/inertial-mems/imu/eval-adcm_kit-installation_and_user_guide.pdf

 Some questions regarding AdcmXL3021 work in MFFT/AFFT mode 

At first , I thought that the calculation of FFT data rate is  4096/(220KSPS /AVG_CNT/FFT_AVG)

But the user guide P.11 says that it takes 1.8 seconds at below settings as below.

On the left panel, use the slider to find the Register called FFT_AVG1. Use the pointer to select this register after which the register name will appear in the top center of the Register access window. Enter “102” in the New Hex Value entry and push the “Write” button. (This configures SR0 FFT averaging to 2, and leaves SR1 rate at the default value. For further information regarding the sample rate configuration please refer to the datasheet of the product.) This selection along with the above AVG_CNT setting, sets the device for a capture duration of 1.8 seconds.

I thought that the data rate at above condition is 4096/220Ksps/2/2 =74ms.

But , EZ Q&A say below.

"I suspect that the majority of the 1.8 seconds will come from the processing time, after the data has been collected."

I can not find the description of processing time in the ADCMXL3021 datasheet.

Please let me know how I should calculate the data rate of FFT.

Regards,

Teli