Power Distribution of Silicon Labs Explorer Kit XG24-EK2703A

Power Distribution of Silicon Labs Explorer Kit XG24-EK2703A

The power topology diagram for the EFR32xG24 Explorer Kit (as shown above) illustrates the board’s power input, conversion, and distribution mechanisms. The core design relies on USB power supply, supports external power input, and integrates automatic isolation and low power optimization to ensure stable system operation and energy efficiency.

Power Input and Conversion

1. USB Type-C Power Input

  • Input Voltage: 5V (supplied by the USB bus)
  • Interface Function: Provides both power and a debugging communication interface
  • Current Capability: Dependent on the USB host

2. LDO Regulator

  • Conversion Function: Steps down the 5V USB input to 3.3V (VMCU) to power the core chip and peripherals
  • Output Characteristics: Low noise and high stability, meeting the power quality requirements of the EFR32MG24
  • Efficiency: Typical efficiency of approximately 85%, suitable for low-power scenarios

3. Automatic Isolation Circuit

  • Working Mechanism: Automatically disconnects the LDO from the USB power supply when the USB cable is disconnected, preventing reverse current from external power sources into the USB interface
  • Components: Isolation circuit based on diodes or MOSFETs to ensure safe power paths

Power Distribution

1. Core Power Rails

  • VMCU (3.3V): Output from the LDO, powers the EFR32MG24 main chip, memory, peripherals, and some expansion interfaces (e.g., mikroBUS, Qwiic).
  • 5V: Directly from the USB input, exposed via breakout pads and the mikroBUS socket for external modules requiring 5V power (e.g., sensors, displays).
  • 3V3 (LDO Output): Common rail with VMCU, provides stable 3.3V power via breakout pads.

2. External Power Input

  • Input Condition: 3.3V external power can only be injected via the VMCU pin when the USB cable is removed and no other power source is connected to the board.
  • Technical Note: Simultaneously connecting USB and external power sources can cause power conflicts, potentially damaging the LDO or main board. Always follow the “single power input” principle.

Conclusion

The power topology of the EFR32xG24 Explorer Kit is designed with USB power as the primary source and external power as a backup, combined with automatic isolation and low power technologies. This ensures system stability while meeting the energy-saving and convenience requirements of IoT applications. Developers can choose USB power supply (debugging mode) or external power (standalone operation mode) based on the scenario, and must pay attention to the selection of power input to avoid hardware damage.

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