SWRA640G December   2018  – September 2022 CC1310 , CC1312R , CC1314R10 , CC1350 , CC1352P , CC1352R , CC1354P10 , CC1354R10 , CC2620 , CC2630 , CC2640 , CC2640R2F , CC2640R2F-Q1 , CC2642R , CC2642R-Q1 , CC2650 , CC2652P , CC2652R , CC2652R7 , CC2652RB , CC2652RSIP , CC2662R-Q1 , CC2674P10 , CC2674R10

 

  1.   Trademarks
  2.   CC13xx/CC26xx Hardware Configuration and PCB Design Considerations
  3. 1 Reference Design
    1. 1.1 Sub-1 GHz LaunchPads
      1. 1.1.1 LAUNCHXL-CC1310
      2. 1.1.2 LAUNCHXL-CC1312R
    2. 1.2 2.4 GHz LaunchPads
      1. 1.2.1 LAUNCHXL-CC2640R2
      2. 1.2.2 LAUNCHXL-CC26x2R
    3. 1.3 Dual-Band LaunchPads
      1. 1.3.1 LAUNCHXL-CC1350EU/US
      2. 1.3.2 LAUNCHXL-CC1350-4
      3. 1.3.3 LAUNCHXL-CC1352R
      4. 1.3.4 LAUNCHXL-CC1352P1
      5. 1.3.5 LAUNCHXL-CC1352P-2
      6. 1.3.6 LAUNCHXL-CC1352P-4
    4. 1.4 Reference Design Overview
  4. 2 Front-End Configurations
    1. 2.1 CC13xx/CC26xx
    2. 2.2 Configuring Front-End Mode
    3. 2.3 CC13xx Single-Ended Mode
      1. 2.3.1 Single-Ended RX/TX
      2. 2.3.2 Single-Ended TX Only
      3. 2.3.3 Single-Ended RX Only
      4. 2.3.4 Single-Ended 2.4 GHz
    4. 2.4 CC26xx
  5. 3 Schematic
    1. 3.1 Schematic Overview
      1. 3.1.1 24/48 MHz Crystal
      2. 3.1.2 32.768 kHz Crystal
      3. 3.1.3 Balun
      4. 3.1.4 Filter
      5. 3.1.5 RX_TX Pin
      6. 3.1.6 Decoupling Capacitors
      7. 3.1.7 Antenna Components
      8. 3.1.8 RF Shield
      9. 3.1.9 I/O Pins Drive Strength
    2. 3.2 Bootloader Pins
    3. 3.3 AUX Pins
      1. 3.3.1 CC26x2/CC13x2 AUX Pins
      2. 3.3.2 CC26x0/CC13x0 AUX Pins
    4. 3.4 JTAG Pins
  6. 4 PCB Layout
    1. 4.1  Board Stack-Up
    2. 4.2  Balun
    3. 4.3  LC Filter
    4. 4.4  Decoupling Capacitors
    5. 4.5  Placement of Crystal Load Capacitors
    6. 4.6  Current Return Path
    7. 4.7  DC/DC Regulator
    8. 4.8  Antenna Matching Components
    9. 4.9  Transmission Lines
    10. 4.10 Electromagnetic Simulation
  7. 5 Antenna
    1. 5.1 Single-Band Antenna
    2. 5.2 Dual-Band Antenna
      1. 5.2.1 Dual-Band Antenna Match Example: 863-928 MHz and 2.4 GHz
      2. 5.2.2 Dual-Band Antenna Match: 433-510 MHz and 2.4 GHz
  8. 6 Crystal Tuning
    1. 6.1 CC13xx/CC26xx Crystal Oscillators
    2. 6.2 Crystal Selection
    3. 6.3 Tuning the LF Crystal Oscillator
    4. 6.4 Tuning the HF Oscillator
  9. 7 TCXO Support
    1. 7.1 Hardware
    2. 7.2 Software
    3. 7.3 Example: Usage of TCXO on CC1312R Launchpad
  10. 8 Integrated Passive Component (IPC)
  11. 9 Optimum Load Impedance
  12. 10PA Table
  13. 11Power Supply Configuration
    1. 11.1 Introduction
    2. 11.2 DC/DC Converter Mode
    3. 11.3 Global LDO Mode
    4. 11.4 External Regulator Mode
  14. 12Board Bring-Up
    1. 12.1 Power On
    2. 12.2 RF Test: SmartRF Studio
    3. 12.3 RF Test: Conducted Measurements
      1. 12.3.1 Sensitivity
      2. 12.3.2 Output Power
    4. 12.4 Software Bring-Up
    5. 12.5 Hardware Troubleshooting
      1. 12.5.1 No Link: RF Settings
      2. 12.5.2 No Link: Frequency Offset
      3. 12.5.3 Poor Link: Antenna
      4. 12.5.4 Bluetooth Low Energy: Device Does Advertising But Can Not Connect
      5. 12.5.5 Poor Sensitivity: DCDC Layout
      6. 12.5.6 Poor Sensitivity: Background noise
      7. 12.5.7 High Sleep Power Consumption
  15. 13References
  16. 14Revision History

12.5.4 Bluetooth Low Energy: Device Does Advertising But Can Not Connect

If using the 32 kHz crystal oscillator as RTC source:

If using the 32 kHz RC oscillator as RTC source:

  • Calibration is not configured correctly. For more information, see the Bluetooth Low Energy Stack User's Guide that is provided with the SDK.

Incorrect RTC frequency will lead to the device missing the connection events and thus breaking the link with the central device.

To debug this problem, the 32 kHz clock can be output on an I/O pin and measured with a frequency counter. For more information on how to do this, see the I/O chapter in the CC13x0, CC26x0 SimpleLink™ Wireless MCU Technical Reference Manual and the C13x2, CC26x2 SimpleLink™ Wireless MCU Technical Reference Manual. By outputting the clock on a pin, you will always measure the _selected_ RTC clock source, as well as be able to measure without affecting the clock source (which probing the crystal for example will do).

If using a 32.768 kHz crystal make sure the crystal part is within the requirements outlined in the device-specific CC13xx/CC26xx data sheets. Also make sure that the load capacitors are dimensioned properly as shown in Section 6.3.

Verify that the BLE-Stack has been configured with the correct Sleep Clock Accuracy. The default setting is 40 ppm and can be adjusted with the HCI_EXT_SetSCACmd API, see hci.h or the TI Vendor Specific API Guide included in the SDK.