SWRA370A September   2011  – December 2025 CC1100 , CC1101 , CC2500 , CC2510 , CC2520 , CC2530 , CC2530-RF4CE , CC2540 , CC2540T , CC2541 , CC2541-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Acronyms
  5. 2Standards and System Requirements
    1. 2.1 Standards
    2. 2.2 Test Equipment Suppliers
    3. 2.3 Radio Certification URLs
  6. 3Test Equipment Requirements
    1. 3.1 System Setup
      1. 3.1.1 Conducted Test Systems
      2. 3.1.2 Radiated Test Systems
    2. 3.2 Initial Considerations for Testing
    3. 3.3 Testing Reminders
  7. 4Software Setup
    1. 4.1 SmartRF Studio 7
      1. 4.1.1 SmartRF Studio 7 Start-Up Window
      2. 4.1.2 SmartRF Studio 7 Modes
      3. 4.1.3 SmartRF Studio 7 Device Control Panel
      4. 4.1.4 SmartRF Studio 7 Software User Manual
    2. 4.2 SmartRF Studio 8
      1. 4.2.1 SmartRF Studio 8 Start-Up Window
      2. 4.2.2 SmartRF Studio 8 Radio Control Window
      3. 4.2.3 SmartRF Studio 8 Software User Guide
  8. 5DUT and Test Instrument Information
    1. 5.1 DUT
    2. 5.2 Test Instruments
  9. 6Clock Frequency Tuning
    1. 6.1 HF Clock Tuning Utilizing the Internal Cap Array
    2. 6.2 LF Clock Tuning
  10. 7Transmission Tests
    1. 7.1 Transmission Power
    2. 7.2 Power Spectral Density Mask
    3. 7.3 Error Vector Magnitude
    4. 7.4 Transmission Center Frequency Offset
    5. 7.5 Spurious Emissions
  11. 8Receive Testing
    1. 8.1 Receiver Sensitivity
    2. 8.2 Interference Testing
    3. 8.3 Interference Testing with RF Generator
  12.   Appendix A Offset EVM vs. EVM
  13.   B References
  14.   B Revision History

6.1 HF Clock Tuning Utilizing the Internal Cap Array

Purpose: Adjusts the device's internal cap array setting for tuning the HF crystal clock accuracy to meet the crystal clock accuracy spec.

Pass Condition: Commanded RF output frequency is within crystal data sheet's specified tolerances with final cap array setting.

High Frequency Clock Tuning Setup Diagram Figure 6-1 High Frequency Clock Tuning Setup Diagram
High Frequency Clock Tuning Bench Setup Figure 6-2 High Frequency Clock Tuning Bench Setup

Procedure:

  • Step 1: Connect the instruments as shown in Figure 6-1 and Figure 6-2.
  • Step 2: Open SmartRF Studio and select the desired frequency on RF Parameters.
  • Step 3: Checkmark (enable) the Cap-Array Tuning. Start with the Cap-Array at 0.
  • Step 4: At the Continous TX tab, make sure the TX is unmodulated and click start.
  • Step 5: Measure the output frequency on the spectrum analyzer.
  • Step 6: If the measured frequency is out of tolerance for the frequency commanded, stop the output signal and then change the Cap-Array (Delta) value depending on required adjustment. If the measured frequency is above the commanded frequency, increase the Cap-Array Setting. If measured frequency is below the commanded frequency, decrease the Cap-Array Setting.
  • Step 7: Enable the RF output and remeasure the output frequency.
  • Step 8: Repeat Steps 6-7 until a Cap-Array Delta value which generates a measured frequency that is as close to the commanded frequency as possible is found.
Note: Ensure the RBW and frequency span of the spectrum analyzer are reduced to ensure the measured frequency resolution is at least within the hundreds of Hz. Also, it is recommended to use a spectrum analyzer with a precision frequency reference for best accuracy. For custom applications, please refer to SWRA495 for help with crystal selection and implementation.
Table 6-2 HF Oscillator Results
Cap-Array Value Chosen Frequency Output Frequency Frequency Delta PPM
1
2
3
4