C8051F850-DK-UG Datasheet, PDF (15/36 Pages) Silicon Laboratories – UDP C8051F850 MCU CARD USER’S GUIDE FOR C8051F85X/86X MCUS

C8051F850-DK-UG
8. Power Measurement
The C8051F850 MCU card includes a JP2 Imeasure jumper for MCU power measurement purposes. The VDD
supply on pin 2 of the header connects only to the MCU on the board. The VDD pre-measure (VDD_PM) supply on
pin 1 of the JP2 header powers the external LEDs, switches, reset switch, potentiometer, and VCP COM.
8.1. Measuring Power with Fixed VDD
To measure the power of the C8051F850 MCU using the MCU card at a fixed 3.3 V:
1. Connect a USB Debug Adapter to the 10-pin shrouded debug connector (J23).
2. Remove the three shorting blocks from J7.
3. Remove the JP2 Imeasure shorting block.
4. Connect a multimeter across (positive side on the left pin, current flow indicated by the silk screen arrow).
5. Move the VDD Select switch (SW2) to the upper +3.3V_VREG position.
6. Connect the 9 V power adapter to POWER (J6).
7. Download the code to the board.
8. Remove the debug adapter connection.
9. Measure the power of the device.
2
6
USB Debug
Adapter
4
1
8
3
5
+000.500 µADC
Figure 10. C8051F850 MCU Card Power Measurement Configuration— Fixed VDD
Rev. 0.2
15