ADRV9009: RxQEC Init Cal: Error configuring Cal PLL

I see RxQEC fail near 6GHz on our custom board. The error messages that I get are:

  • TALISE_waitInitCals: Talise init calibration error encountered
  • TALISE_getInitCalStatus: RxQEC Init Cal: Error configuring Cal PLL

From what I've read, the user doesn't really have much control/visibility of the Cal PLL. Are there any suggestions for debugging/investigating this?

The return code from TALISE_waitInitCals is TALACT_ERR_RERUN_INIT_CALS, but re-running the init cals results in the same error.

If I set the RX frequency to something a bit lower, I *am* able to then change the frequency to 6GHz (and successfully re-run init cals).

  • +1
    •  Analog Employees 
    on Jun 5, 2020 8:27 AM 9 months ago

    Please refer below from user guide.

    ADRV9008-1 and ADRV9009 Receiver QEC Initial Calibration
    The receiver QEC initialization calibration algorithm is utilized to improve the receiver path QEC performance. The receiver QEC
    calibration sweeps a number of internally generated test tones across the band, measures quadrature performance, and calculates
    correction coefficients. The input port must be isolated from incoming signals. The calibration tones appear on the receiver pins. The calibration tones must be prevented from reaching the antenna by properly terminating the receiver port.
    Note that the auxiliary PLL is used to generate the tones of the receiver QEC initialization calibration (CalPLL in Figure 106). Operation
    of the auxiliary PLL must be limited to 6.061 GHz. For RF LO frequencies close to the maximum frequency, 6 GHz, the frequency limit of the auxiliary PLL must be taken into consideration. The auxiliary PLL generates tones in the RF frequency by sweeping across the
    baseband bandwidth. The range that the auxiliary PLL sweeps the tones across is RF LO frequency – baseband bandwidth/2 to RF LO
    frequency + baseband bandwidth/2. A 200 MHz profile at an RF LO frequency of 6 GHz causes a conflict because the auxiliary PLL must generate tones up to 6.1 GHz. In this case, the recommendation is to change the RF LO frequency for the initialization calibration so that the maximum frequency generated by the auxiliary PLL is 6.061 GHz (RF LO frequency + baseband bandwidth/2 ≤ 6.061 GHz). The RF
    LO frequency can be returned to the required setting before operation.

  • Ah I missed that. Thank you, that sounds like the issue. The configuration I'm attempting to use has 164MHz BW and the point at which it fails is roughly 5977.6MHz.

    5977.6MHz+164MHz/2 = 6059.6MHz