C8051F850-DK-UG Datasheet, PDF (16/36 Pages) Silicon Laboratories – UDP C8051F850 MCU CARD USER’S GUIDE FOR C8051F85X/86X MCUS

C8051F850-DK-UG
8.2. Measuring Power with Varying VDD
To measure power with a varying VDD:
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 the JP2 Imeasure jumper (positive side on the left pin, current flow indicated
by the silk screen arrow).
5. Move the VDD Select switch (SW2) to the lower MB position.
6. Connect the negative terminal of a bench power supply to board ground.
7. Connect the positive terminal of a bench power supply to the positive side (left pin) of the Imeasure
jumper. This will ensure that the /RST pin pull-up is powered.
Note: The pull-up resistor on /RST is powered by the VDD pre-measure (VDD_PM) net, which is separated from the VDD net
with the Imeasure shorting block (JP2) removed. Powering the MCU using VDD without powering the VDD_PM net will
prevent the IDE from communicating with the MCU.
8. Download the code to the board.
9. Remove the debug adapter connection.
10. Measure the power of the device.
2
USB Debug
Adapter
1
9
3
5
4
+000.500 µADC
2.8
V
6
7
Figure 11. C8051F850 MCU Card Power Measurement Configuration—Varying VDD
9. Known Board Issues
There are no known issues with Revision 200 of the C8051F850 MCU card.
16
Rev. 0.2