User Manual

nRF51 Development Kit User Guide v1.0

Page 18

5.7 Measuring current

The current drawn by the nRF51422 device can be monitored on the nRF51 DK board. To measure the

current, you must first prepare the board by cutting the shorting of solder bridge SB9.

There are two ways of measuring the current consumption:

1. Connect an ampere-meter between the pins of connector P22. This will monitor the current

directly.

Figure 16 Current measurement with ampere-meter

2. Mount a resistor on the footprint for R6. The resistor should not be larger than 10

Ω. Connect an

oscilloscope in differential mode or similar with two probes on the pins of the P1 connector and

measure the voltage drop. The voltage drop will be proportional with the current consumption.

For example, if a 10

Ω resistor is chosen, 10 mV equals 1 mA.

Figure 17 Current measurement with oscilloscope

Note: The current measurements will become unreliable when a Serial terminal is connected to the

Virtual COM port.

Cut SB9

Add R6