SWRA834 May   2025 CC2340R5 , CC2340R5-Q1 , CC2744R7-Q1 , CC2745P10-Q1 , CC2745R10-Q1 , CC2745R7-Q1 , CC2755R10

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
  5. 2 Reference Designs
    1. 2.1 LP-EM-CC2340R53
    2. 2.2 LP-EM-CC2340R5
    3. 2.3 LP-EM-CC2340R5-Q1
    4. 2.4 LP-EM-CC2340R5-RGE-4x4-IS24
    5. 2.5 LP-EM-CC2745R10-Q1
  6. 3 Schematic
    1. 3.1 Schematic Overview
      1. 3.1.1 48MHz Crystal
      2. 3.1.2 32.768kHz Crystal
      3. 3.1.3 Filter
      4. 3.1.4 Decoupling Capacitors
      5. 3.1.5 Antenna Components
      6. 3.1.6 RF Shield
    2. 3.2 I/O Pins Drive Strength
    3. 3.3 Bootloader Pins
    4. 3.4 Serial Wire Debug (SWD) Pins
  7. 4 PCB Layout
    1. 4.1 Board Stack-Up
    2. 4.2 LC Filter
    3. 4.3 Decoupling Capacitors
    4. 4.4 Placement of Crystal Load Capacitors
    5. 4.5 Current Return Path
    6. 4.6 DC/DC Regulator
    7. 4.7 Antenna Matching Components
    8. 4.8 Transmission Lines
    9. 4.9 Electromagnetic Simulation
  8. 5 Antenna
  9. 6 Crystal Tuning
    1. 6.1 CC23xx and CC27xx Crystal Oscillators
    2. 6.2 Crystal Selection
    3. 6.3 Tuning the LF Crystal Oscillator
    4. 6.4 Tuning the HF Crystal Oscillator
  10. 7 Optimum Load Impedance
  11. 8 PA Table
  12. 9 Power Supply Configuration
    1. 9.1 Introduction to Power Supply
    2. 9.2 DC/DC Converter Mode
    3. 9.3 Global LDO Mode
  13. 10Board Bring-Up
    1. 10.1 Power On
    2. 10.2 RF Test: SmartRF Studio
    3. 10.3 RF Test: Conducted Measurements
      1. 10.3.1 Sensitivity
      2. 10.3.2 Output Power
    4. 10.4 Hardware Troubleshooting
      1. 10.4.1 No Link: RF Settings
      2. 10.4.2 No Link: Frequency Offset
      3. 10.4.3 Poor Link: Antenna
      4. 10.4.4 Bluetooth Low Energy: Device Does Advertising But Cannot Connect
      5. 10.4.5 Poor Sensitivity: Background Noise
      6. 10.4.6 High Sleep Power Consumption
  14. 11Summary
  15. 12References

10.2 RF Test: SmartRF Studio

To use SmartRF Studio for testing, the board needs a connector that enables a debugger to be connected directly to the RF chip. Use a LP-XDS110/LP-XDS110ET for the CC23xx and CC27xx. The required pins to be connected are VDDS (not required when the device is powered externally), GND, RESET, SWDIO and SWDCK.

  1. Connect a debugger to the board. Open SmartRF Studio and verify that the device is visible in the list of connected devices.
  2. Place two known, good boards with 2m distance. In this context, known, good boards are LaunchPads from TI. Use a predefined PHY setting in SmartRF Studio that is a closest match to the PHY that is used in the final product.
  3. Set one board to Packet RX and the other to Packet TX and transmit 100 packets. Confirm that the packets are received and note the RSSI for the received packets.
  4. Replace the board used in TX with the device under test (DUT). Repeat the test described in #3.
  5. Replace the board used in RX with the DUT. Replace the board used in TX with a good known board. Repeat the test described in #3.
  6. If possible, then the measurements need to be done with a known, good antenna first and then repeated with the antenna that is going to be used in the final design later. A poorly tuned antenna can cause significant loss in sensitivity or output power.
  7. If the results are satisfactory, then change the settings from the predefined setting to the RF settings planned to be used in the final product. Repeat the tests described in #3 to #5 with the wanted RF settings.

If the RSSI deviates from the reference, then review the schematic and layout.