AWR1642BOOST: 1) minimum number of ADC samples - - 2) 90~99% settling

Alper Fatih

Expert 1040 points

Part Number: AWR1642BOOST
Other Parts Discussed in Thread: AWR1642

Hi,

I have a few basic questions.

1- I understand that that the Minimum value value for ADC sampling rate is 2Msps or 2000 ksps.

For AWR1642BOOST, maximum ADC sampling rate for 1x COMPLEX mode is (0.9x6.25=5.625 MHz) or it is 5625 ksps.

For AWR1642BOOST, maximum ADC sampling rate for REAL and 2x COMPLEX mode is ( (0.9x6.25)/2= 2.8125 MHz) or it is 28125.5 ksps.

Please confirm is my above understanding correct, both in terms of sampling frequency and in terms of ksps ?

2- As an example, please refer the user guide for mmwave sdk 2.0.0.4 (document number Product Release 2.0.0 , Release date 26 April, 2018, Document version 1.0 ) , page 16, 17. Please also refer user guide for mmwave sdk 3.3.0.3 (document number Product Release 3.3 , Release date 17 Sept, 2019, Document version 1.0 ) , page 21.

The following formula is given : (<numAdcSamples> / <digOutSampleRate> = "ADC Sampling Time")

My question are :

3- Although the user guide for mmwave sdk 3.3.0.3 states that value of less than 64 has not been validated for number of ADC samples, however, is there any theoretical and / or practical MINIMUM and MAXIMUM limits for number of ADC samples. Please refer a relevant TI document as well. In fact, I am more interested in MINIMUM number of ADC samples allowed / permissible.

4- The Ramp Timing Calculator in mmwave Studio shows 90 % Settling, 95% Settling, 99 % Settling. Can you please elaborate what exactly is meant by this ?

Thanks and best regards

over 5 years ago

0 Kyle Cousino over 5 years ago

TI__Mastermind 24955 points

Alper,

Please refer to the AWR1642 datasheet for this information, found here: http://www.ti.com/lit/ds/symlink/awr1642.pdf

The maximum complex sampling rate is 6.25 Msps and the maximum real sampling rate is 12.5 Msps. This is found on page 7.

You can also look at the Doxygen in SDK v3.3 to see what the minimum and maximum number of ADC samples allowed by the device firmware is. You can find this in the "numAdcSamples" variable explanation.

You can find this file here: file:///C:/ti/mmwave_sdk_03_03_00_03/packages/ti/control/mmwavelink/docs/doxygen/html/structrl_profile_cfg__t.html

Please refer to the mmWave Studio User's Guide, section 15, for more information on the ramp timing calculator.

Regards,

Kyle

0 Alper Fatih over 5 years ago in reply to Kyle Cousino

Expert 1040 points

Hi Kyle,

Thank you very much for your very precise and concise response.

1- I would have probably never been able to reach, on my own, at the information about the doxygen link that you advised, about the minimum number of ADC samples. Thanks

Just a reconfirmation at this point, as I do not find this information in the datasheet :

For AWR1642BOOST, Minimum value value for ADC sampling rate is 2Msps or 2000 ksps and it is same for REAL, 1x COMPLEX and 2x COMPLEX modes. Is my understanding correct ?

2- I think I made a mistake or overlook about maximum ADC sampling rate. Thanks for the correction.

I now understand that, for AWR1642BOOST, maximum ADC sampling rate for 2x COMPLEX modes is ( (0.9x12.5)/2= 5.625 MHz) or it is 5.625 ksps.

3- I have, again, referred the section 15 of mmwave Studio User Guide for Ramp Timing Calculator but that does not explain Settling Time.

I, myself, understand that, for example, 95% Settling means that, at the given time parameter (e.g ADC Start Time, Ramp End Time) and whole recommended configuration, the output frequency will achieve 95% of the set value for frequency. Is my understanding correct ?

Thanks and regards

Sensors

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AWR1642BOOST: 1) minimum number of ADC samples - - 2) 90~99% settling