EZRadioPRO-DK
5.2. Power Scheme
The power source of the platform can be selected with the power supply selector switch “SUPPLY SELECT” on the
WMB board. If this switch is in the ”USB” position, supply voltage is provided by the PC that is connected to the
”J16” mini USB connector. If this switch is in the ”BAT” position, the supply voltage is provided by two AA batteries
in the battery holder on the bottom side of the board. If the ”SUPPLY SELECT” switch is in the ”EXT” position,
supply voltage is provided by an external power source through the ”TP7” and “TP9” points.
Using the ”MCU dc/dc” switch, the internal dc/dc converter of the C88051F930 MCU on the MCU pico board can
be activated if the connected pico board supports this function. If the switch is in ”OFF” position, the MCU's dc/dc
converter is inactive and the supply voltage is only determined by the state of the “SUPPLY SELECT” switch.
Positioning the switch to either ”LDO (1.25 V)” or ”1 CELL” position will turn on the MCU's dc/dc converter by
connecting 1.25–1.5 V supply voltage to the VBAT pin and removing external power from the VDC pin. The MCU
will provide 1.9 V in default setting on its VDC pin to all the other connected loads. Since this current is limited, it
may be necessary to disconnect or disable some loading part of the board. For further details, see the MCU data
sheet and the board schematic. The board schematic can be found in the EZRadioPRO Development Kit User's
Guide. A complete CAD design pack of the board is also available at www.silabs.com.
5.3. RF Pico Board
Figure 5. RF Pico Board Front Side
The RF pico board is a radio module that contains an EZRadioPRO radio IC, matching network and an SMA
connector on the top side. These components apart from the antenna connector are covered by a metal shield for
noise reduction. The digital signals of the radio (SCLK, SDI, SDO, NSEL, SCL, SDA, VDD and GND) can be
accessed on test points at the edge of the board. The boards also have a factory loaded board identification
memory (EBID) on the bottom side that contains data that describes the board properties. Via the unified RF pico
connector pair on the bottom side of the board, any RF pico board can be connected to the WMB.
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Rev. 0.5
SILICON [ SILICON ]
