SPRACF4C June   2018  – January 2023 AWR1243 , AWR1443 , AWR1642 , AWR1843 , AWR1843AOP , AWR2243 , AWR2944 , AWR6843 , AWR6843AOP , IWR1843 , IWR6443 , IWR6843 , IWR6843AOP

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Purpose of Calibrations
    2. 1.2 Purpose of Monitoring Mechanisms
  3. 2Hardware Infrastructure to Support Calibration and Monitoring
  4. 3List of Calibrations
    1. 3.1  APLL Calibration
    2. 3.2  Synthesizer VCO Calibration
    3. 3.3  LO Distribution Calibration
    4. 3.4  ADC DC Offset Calibration
    5. 3.5  HPF Cutoff Calibration
    6. 3.6  LPF Cutoff Calibration
    7. 3.7  Peak Detector Calibration
    8. 3.8  TX Power Calibration
    9. 3.9  RX Gain Calibration
    10. 3.10 IQ Mismatch Calibration
    11. 3.11 TX Phase Shifter Calibration
  5. 4Impact of Calibration on Gain and Phase
  6. 5Impact of Interference on the Calibrations and Emissions Caused Due to Calibrations
  7. 6Scheduling of Runtime Calibration and Monitoring
    1. 6.1 Selection of CALIB_MON_TIME_UNIT
    2. 6.2 Selection of CALIBRATION_PERIODICITY
    3. 6.3 Application-Controlled One Time Calibration
  8. 7Software Controllability of Calibration
    1. 7.1  Calibration and Monitoring Frequency Limits
    2. 7.2  Calibration and Monitoring TX Frequency and Power Limit
    3. 7.3  Calibration Status Reports
      1. 7.3.1 RF Initialization Calibration Completion
      2. 7.3.2 Runtime Calibration Status Report
      3. 7.3.3 Calibration/Monitoring Timing Failure Status Report
    4. 7.4  Programming CAL_MON_TIME_UNIT
    5. 7.5  Calibration Periodicity
    6. 7.6  RF Initialization Calibration
    7. 7.7  Runtime Calibration
    8. 7.8  Overriding the TX Power Calibration LUT
    9. 7.9  Overriding the RX Gain Calibration LUT
    10. 7.10 Retrieving and Restoring Calibration Data
  9. 8References
  10.   A Calibration and Monitoring Durations
    1.     A.1 Duration of Boot Time Calibrations
  11.   Revision History

3.1 APLL Calibration

The APLL (or cleanup PLL) is a closed loop PLL that takes the 40-Mhz reference clock as input and generates the clocks required for the processor, digital logic as well as the ADCs, DACs, and FMCW synthesizer. In the AWR2944/43, the ADCs, DACs, and FMCW synthesizer are run by APLL; the digital processors in the device are run by ADPLLs. APLL calibration is done to keep the system clock always locked at a constant frequency irrespective of process and temperature. It is done at the RF initialization phase by measuring the VCO’s control voltage and adjusting the VCO tuning.

This is periodically and incrementally repeated at run time to account for the temperature drift. Runtime APLL calibration is triggered when the age of the last calibration result exceeds 1 second. Due to the importance of the system clock, APLL calibration cannot be disabled by the user and the calibration periodicity is not user controllable. The user should account for this calibration time while programming the frame timing.