nRF7002 DK v1.0.0

Using an oscilloscope for current profile measurement

An oscilloscope can be used to measure both the average current over a given time interval and capture the current profile.

Make sure you have followed the instructions in Preparing the nRF7002 DK.
  1. Mount a 10 Ω resistor on the R91 footprint.
  2. Connect an oscilloscope in differential mode or similar with two probes on the pins of the P23 connector, as shown in the following figure.
  3. Calculate or plot the instantaneous current from the voltage drop across the 10 Ω resistor by taking the difference of the voltages measured on the two probes. The voltage drop is proportional to the current. The 10 Ω resistor causes a 10 mV drop for each 1 mA drawn by the circuit being measured.

The plotted voltage drop can be used to calculate the current at a given point in time. The current can then be averaged or integrated to analyze current and energy consumption over a period.

Figure 1. Current measurement with an oscilloscope
nRF7002 DK current measurement with an oscilloscope
Do the following to reduce noise:
  • Use probes with 1x attenuation.
  • Enable averaging mode to reduce random noise.
  • Enable high resolution function if available.
A minimum of one sample every 5 µs is needed to accurately measure the average current.