SWRZ166A November   2024  – June 2025 AWR2944P

 

  1.   1
  2. 1Introduction
  3. 2Device Nomenclature
  4. 3Device Markings
  5. 4Advisory to Silicon Variant / Revision Map
  6. 5Known Design Exceptions to Functional Specifications
    1.     MSS#25
    2.     MSS#27
    3.     MSS#28
    4.     MSS#29
    5.     MSS#30
    6.     MSS#33
    7.     MSS#40
    8. 5.1  MSS#49
    9. 5.2  MSS#53
    10. 5.3  MSS#54
    11. 5.4  MSS#55
    12. 5.5  MSS#56
    13. 5.6  MSS#57
    14. 5.7  MSS#61
    15. 5.8  MSS#62
    16.     MSS#66
    17. 5.9  MSS#67
    18.     MSS#69
    19.     MSS#70
    20. 5.10 ANA#12A
    21.     ANA#37A
    22.     ANA#39
    23.     ANA#43
    24.     ANA#44
    25.     ANA#45
    26.     ANA#46
    27.     ANA#47
    28.     ANA#58
  7.   Trademarks
  8.   Revision History

ANA#58

Spurs Caused due to Digital Activity [AWR2944P]

Revision(s) Affected:

AWR2944P, AWR2944-ECO, AWR2944LC

Description:

Digital filtering activity can potentially couple to analog circuits leading to spurs in the LO, which can also be seen in the Rx data. Such a spur in the Rx data can be seen at the spur frequency offset around a strong object. This effect is dependent on customer board design, configuration, XTAL frequency and signal processing and can not occur or affect a given design.

The following are the different spurs that can potentially be observed for XTAL frequency=50MHz, for DFE Sampling rate Fs:

  • Spurs at (2Fs-50)MHz IF frequency for sampling rate +/-1Msps around 25Msps.
  • Spurs at (4Fs-150)MHz and its harmonic IF frequencies for sampling rate +/-0.5Msps around 37.5Msps.
  • Spurs at (Fs-50)MHz and its harmonic IF frequencies for sampling rate 40 to 45Msps.
  • Spurs at (2Fs-100)MHz and its harmonic IF frequencies for sampling rate 30 to 45Msps.

Corresponding to the spurs listed above, below are the different spurs that can potentially be observed for XTAL frequency=40MHz, for DFE Sampling rate Fs:

  • Spurs at (2Fs-40)MHz IF frequency for sampling rate +/-1Msps around 20Msps.
  • Spurs at (4Fs-120)MHz and its harmonic IF frequencies for sampling rate +/-0.5Msps around 30Msps.
  • Spurs at (4Fs-140)MHz IF frequency for sampling rate +/-0.5Msps around 35Msps.
  • Spurs at (Fs-40)MHz and its harmonic IF frequencies for sampling rate +/-1Msps around 40Msps.
  • Spurs at (2Fs-100)MHz and its harmonic IF frequencies for sampling rate 30 to 45Msps.

Additionally, `below are other spurs that can potentially be observed for XTAL frequency=40MHz, for DFE Sampling rate Fs:

  • Spurs at (2Fs-10)MHz IF frequency for sampling rate +/-0.5Msps around 5Msps.
  • Spurs at (2Fs-15)MHz IF frequency for sampling rate +/-0.5Msps around 7.5Msps.
  • Spurs at (2Fs-38)MHz IF frequency for sampling rate +/-0.5Msps around 19Msps.
  • Spurs at (8Fs-260)MHz IF frequency for sampling rate +/-0.2Msps around 32.5Msps.

Workaround(s):

The user can check the design for occurrence and if necessary avoid sampling rates in the range mentioned above or use exactly the center of the sampling rate range (so that spur is at 0Hz).