Silicon Labs AN969 User Manual
AN969: Measuring Power Consumption on
Wireless Gecko Devices
Silicon Labs offers a complete portfolio of fully-certified modules
SoC solutions known collectively as the Wireless Gecko de-
and
vices. This application note explains how to measure the power
consumption of these devices.
The setup and procedure recommended for measuring the power consumption of Wireless Gecko devices are presented here in detail. As a reference, an example is given
where the current profile of an EFR32BG1 SoC is captured with a DC power analyzer
to determine power and energy consumption figures.
Alternative methods for measuring power consumption, such as the Energy Profiler tool
in Simplicity Studio, are also discussed briefly.
Note: The instructions and recommendations in this document apply to the power consumption measurements of any Wireless Gecko device.
KEY POINTS
• A Wireless Gecko WSTK is required.
•
The test device must be programmed with
a suitable test application.
• Three methods to capture power
measurements are discussed,
emphasizing the DC power analyzer since
it gives the best results.
• Simplicity Studio’s Energy Profiler yields
comparable average measurements to
those from a DC power analyzer at a
fraction of the cost.
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AN969: Measuring Power Consumption on Wireless Gecko Devices
Documentation
1. Documentation
The documents listed below (sorted by topic) may be helpful during the evaluation. You may download them directly from www.si-
labs.com after registering and creating a user account, or you may navigate through Simplicity Studio's documentation interface to find
them and then download them.
Hardware
• The applicable Wirelesss Starter Kit User's Guide
• The applicable radio board reference manual
Software and Tools
• AN0822: Simplicity Studio User Guide (for Simplicity Studio 4)
• Simplicity Studio 5 User’s Guide, available at https//docs.silabs.com and through the Simplicity Studio 5 help menu
• UG343: Multi-Node Energy Profiler User’s Guide
• AN0948: Power Configurations and DC-DC
• AN1246: EFR32BG SoC Bluetooth® Smart Device Power Consumption Measurements
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AN969: Measuring Power Consumption on Wireless Gecko Devices
2. Setup
To evaluate power consumption you will need the following:
1. Obtain a Wireless Starter Kit and radio board.
2. Build and install a suitable test application.
3. Configure the WSTK as described in section 2.3 Configuring the WSTK Main Board.
Setup
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AN969: Measuring Power Consumption on Wireless Gecko Devices
2.1 Wireless Starter Kit Overview
As seen in the figure below, the Wireless Gecko Wireless Starter Kit consists of three components:
• The Wireless Starter Kit (WSTK) main board
• The Radio Board
• The Expansion Board (included in WSTKs for modules only, not SoCs)
Setup
Figure 2.1. Wireless Gecko Wireless Starter Kit
The actual Wireless Gecko device is contained in the radio board. Therefore, the radio board will vary depending on the Wireless
Gecko device you want to work with (module or SoC). The figures below show the radio boards for a BGM111 module and then for an
EFR32BG1 SoC.
Figure 2.2. Module Radio Board
Figure 2.3. SoC Radio Board
For power measurements, only the WSTK and the radio board are necessary. See the applicable reference manual for details about
the WSTK.
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AN969: Measuring Power Consumption on Wireless Gecko Devices
Setup
2.2 Building and Loading a Test Application
If you have not already done so, install Simplicity Studio and the relevant SDK. Each SDK includes several software examples to create
application projects. Follow the directions in the applicable SDK Quick Start Guide to install Simplicity Studio, and build and flash the
example project to the device.
2.3 Configuring the WSTK Main Board
The WSTK main board supports three options for delivering power to the radio board: (1) through USB, (2) from a coin-cell battery, and
(3) from an external power supply.
For cleaner power measurements, an external supply is the better choice because powering through USB enables other circuitry on the
WSTK main board that may, in some cases, lead to slightly higher or noisier current readings. When powering from a coin-cell battery,
the battery’s series resistance or its limited current-sourcing capability after aging may lead to current consumption profiles with a pronounced exponential rise or decay response that could mask the real power consumption of the device under test (DUT).
To power the Wireless Gecko device from an external source, change the power switch of the WSTK main board to BAT and apply 3.3
V (or your expected main supply voltage) at the nodes highlighted in the figure below (soldering a two-pin header there may be useful).
The silkscreen on the WSTK board shows the polarity of the nodes.
Figure 2.4. WSTK Main Board Powering Options
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