Nordic Semiconductor PCA63511, Руководство пользователя

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Chapter 5
Configuring the Power Profiler Kit
This section describes four different configuration setups for the Power Profiler Kit (PPK) and methods for
current measurement.
To configure the PPK, complete the following steps:
1. For measurement accuracy, some adjustments are needed. For details, see Measurement accuracy
optimization on page 14.
2.
Choose a use case and implement a configuration for the PPK. The options are presented in the following
table.
Table 4: The PPK use cases
Use case Configuration setup/measurement method
Design stage, no custom
hardware
Current measurements on the nRF5x DK on page 15.
Design and optimization stage,
no custom hardware, with
debugging
Current measurements on the nRF5x DK while debugging on page
16.
Current measurements on a custom hardware with nRF5x DK on page
16.
Design stage, using external/
custom hardware
Current measurements on a custom hardware without using an nRF5x
DK on page 18.
5.1 Measurement accuracy optimization
When measuring current with the PPK, some adjustments are needed to optimize the measurement accuracy.
The nRF5x DK must be prepared for the power measurement.
Match voltages between the nRF5x DK and the Power Profiler Kit
In cases where the PPK is used with an nRF5x DK, it is recommended to use the Power select ( SW4 ) switch in
the “DK” position.
Although not recommended, if you need to use the PPK on-board regulator as the power source due to noise
issues (to improve the USB noise filtering), make sure that the PPK regulator voltage exactly matches the
nRF5x DK voltage. Otherwise, current leakage may occur and lead to erroneous current readings.
Considerations when measuring on external DUTs
When measuring current on external devices, it is important to keep in mind that large filtering capacitors
which may be present on the DUT circuit will smooth out the variations in current consumption. This yields a
good result for the average current consumption, but the short current bursts will be filtered out and the plot
might differ from what you see on the measurements done on the nRF5x DK during development.
As a good practice, keep extra decoupling capacitors to a minimum when measuring detailed current draw.
Decoupling capacitors to ensure correct operation of the devices must be included though.