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Renesas RA Family
5.1.1 Power Supply Options
This section describes the different ways in which FPB-RA2E2 board can be powered.
The MCU can be operated at a lower voltage than 3.3 V by removing the current measurement resistor and
powering the MCU via TP1.
Note: Other changes to the circuit where interfaces or pull-up resistors are used may also need to be
removed. Please review the schematic carefully before making these changes.
5.1.1.1 Option 1: Debug USB
5 V may be supplied from an external USB host to the USB debug connector (CN6) labelled POWER on the
board. Power from this source is connected to the main system 5 V power. Reverse current protection is
provided between this connector and the main system 5 V power.
5.1.1.2 Option 2: Header Connector CN5
A standard 2-pin header on a 0.1" (2.54 mm) pitch can be fitted for CN5. 5 V can then be supplied from an
external power supply to this connector. Pin 1 is GND, and pin 2 is +5 V. Power from this source is
connected to the main system 5 V power. Reverse current protection is provided between CN5 and the main
system 5 V power.
5.1.2 Power Supply Considerations
The on-board LDO regulator which supplies +3.3 V has a built-in current limit of 2.0 A. Make sure the total
current required by the RA MCU, any active on-board features, and any connected peripheral devices does
not exceed this limit.
Note: The total current available from a typical USB host is 100 mA before enumeration, and 500 mA
maximum. Depending on the configuration of the kit, multiple power sources may be required.
R20UT4969EG0100 Rev 1.00
May.09.22
Figure 6. Power Supply Options
FPB-RA2E2 v1 – User's Manual
Page 12 of 24
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