Silicon Laboratories UG464 User manual

UG464: Thunderboard™ EFR32BG22
User's Guide
The Thunderboard™ EFR32BG22 is a low cost, small form factor
prototype and development platform for the EFR32BG22 Wireless
Gecko System-on-Chip.
The board is a small and cost effective, feature rich, prototype and development platform
based on the EFR32™ Wireless Gecko System-on-Chip. The Thunderboard
EFR32BG22 is an ideal platform for developing energy-friendly connected IoT devices.
The Thunderboard EFR32BG22 ships with a Bluetooth demo that works with a cloud
connected smartphone app, showcasing easy collection of environmental and motion
sensor data, as well as button and LED control.
A built in SEGGER J-Link debugger ensures easy debugging through the USB Micro-B
connector.
TARGET DEVICE
• EFR32 Wireless Gecko System-on-Chip
(EFR32BG22C224F512IM40)
• 32-bit ARM® Cortex®-M33 with 76.8
MHz maximum operating frequency
• 512 kB flash and 32 kB RAM
• Energy-efficient radio core with low
active and sleep currents
• Bluetooth 5.2 Direction Finding
• Integrated PA with up to 6 dBm (2.4
GHz) TX power
• Secure Boot with Root of Trust and
Secure Loader (RTSL)
KIT FEATURES
• 2.4 GHz ceramic chip antenna
• Power control of on-board peripherals for
ultra low power operation
• Relative humidity and temperature sensor
• Ambient light sensor
• Hall effect sensor
• 6-axis inertial sensor
• PDM stereo microphones
• 8 Mbit flash for OTA programming and
data logging
• User LED and push button
• 20-pin 2.54 mm breakout pads
• SEGGER J-Link on-board debugger
• Virtual COM port
• Packet Trace Interface (PTI)
• Mini Simplicity connector for AEM and
packet trace using external Silicon Labs
debugger
• USB or coin cell battery powered.
SOFTWARE SUPPORT
• Simplicity Studio™
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Table of Contents
1. Introduction ................................4
1.1 Kit Contents ...............................4
1.2 Getting Started ..............................4
1.3 Hardware Content .............................4
1.4 Kit Hardware Layout ............................5
2. Specifications ...............................6
2.1 Recommended Operating Conditions ......................6
2.2 Current Consumption ............................7
3. Hardware .................................9
3.1 Block Diagram ..............................9
3.2 Power Supply ..............................10
3.3 EFR32BG22 Reset ............................10
3.4 Peripherals ...............................11
3.4.1 Si7021 Relative Humidity and Temperature Sensor ................12
3.4.2 Si7210 Hall Effect Sensor .........................12
3.4.3 VEML6035 Ambient Light Sensor ......................13
3.4.4 PDM Stereo Microphones .........................13
3.4.5 ICM-20648 6-Axis Inertial Sensor ......................14
3.4.6 Push Button and LED ..........................15
3.4.7 External Memory ............................15
3.5 On-board Debugger ............................16
3.6 Connectors ...............................17
3.6.1 Breakout Pads ............................18
3.6.2 Mini Simplicity Connector .........................19
3.6.3 Debug USB Micro-B Connector .......................19
4. Debugging ...............................20
4.1 On-board Debugger ............................21
4.2 External Debugger.............................21
4.3 Virtual COM Port .............................22
5. Radio .................................23
5.1 RF Section ...............................23
5.1.1 Description of the RF Matching .......................23
5.1.2 RF Section Power Supply .........................23
5.1.3 RF Matching Bill of Materials ........................23
5.1.4 Antenna ...............................24
5.1.5 Antenna Matching Bill of Materials ......................24
5.2 EMC Regulations for 2.4 GHz .........................24
5.2.1 ETSI EN 300-328 Emission Limits for the 2400-2483.5 MHz Band ...........24
5.2.2 FCC15.247 Emission Limits for the 2400-2483.5 MHz Band .............24
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5.2.3 Applied Emission Limits .........................25
5.3 Relaxation with Modulated Carrier .......................25
5.4 Radiated Power Measurements ........................26
5.4.1 Maximum Radiated Power Measurement ...................26
5.4.2 Antenna Pattern Measurement .......................27
5.5 EMC Compliance Recommendations ......................29
5.5.1 Recommendations for 2.4 GHz ETSI EN 300-328 Compliance ............29
5.5.2 Recommendations for 2.4 GHz FCC 15.247 Compliance ..............29
6. Schematics, Assembly Drawings, and BOM ...................30
7. Kit Revision History ............................31
8. Board Revision History and Errata ......................32
8.1 Revision History .............................32
8.2 Errata .................................32
9. Document Revision History .........................33
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1. Introduction
The Thunderboard EFR32BG22 (OPN: SLTB010A) has been designed to inspire customers to make battery operated IoT devices with
the Silicon Labs EFR32BG22 Wireless Gecko System-on-Chip. The highlights of the board include four different environmental sensors
and stereo PDM microphones accessible to the EFR32BG22 wireless MCU. The peripherals have been grouped into power domains
that can be turned on and off by the application code as needed.
Programming the Thunderboard EFR32BG22 is easily done using a USB Micro-B cable and the on-board J-Link debugger. A USB vir-
tual COM port provides a serial connection to the target application, and the Packet Trace Interface (PTI) offers invaluable debug infor-
mation about transmitted and received packets in wireless links. Included on the board is an 8 Mbit serial flash that can be used for
Over-The-Air (OTA) firmware upgrade, or as a general purpose non-volatile memory. The Thunderboard EFR32BG22 is supported in
Simplicity Studio™, and a Board Support Package (BSP) is provided to give application developers a flying start.
Energy profiling and advanced wireless network analysis and debugging tools are available through the provided Mini Simplicity Con-
nector using an external Silicon Labs debugger.
Connecting external hardware to the Thunderboard EFR32BG22 can be done using the 20 breakout pads which present peripherals
from the EFR32BG22 Wireless Gecko such as I2C, SPI, UART and GPIOs. The breakout pads follow the same pinout as the expansion
headers (EXP) on other Silicon Labs Starter Kits.
1.1 Kit Contents
The following items are included in the box:
• 1x Thunderboard EFR32BG22 board (BRD4184B)
• 1x USB Type A to Micro-B cable.
1.2 Getting Started
Detailed instructions for how to get started with your new Thunderboard EFR32BG22 can be found on the Silicon Labs web pages:
https://www.silabs.com/support/getting-started/thunderboard
1.3 Hardware Content
The following key hardware elements are included on the Thunderboard EFR32BG22:
• EFR32BG22 Wireless Gecko SoC with 76.8 MHz operating frequency, 512 kB kB flash and 32 kB RAM
• 2.4 GHz ceramic antenna for wireless transmission
• Silicon Labs Si7021 relative humidity and temperature sensor
• Silicon Labs Si7210 hall effect sensor
• Vishay VEML6035 ambient light sensor
• TDK InvenSense ICM-20648 6-axis inertial sensor
• Two Knowles SPK0641HT4H-1 MEMS microphones
• Macronix ultra low power 8 Mbit SPI flash (MX25R8035F)
• One LED and one push button
• Power enable signals and isolation switches for ultra low power operation
• On-board SEGGER J-Link debugger for easy programming and debugging, which includes a USB virtual COM port and Packet
Trace Interface (PTI)
• Mini Simplicity connector for access to energy profiling and advanced wireless network debugging
• Breakout pads for GPIO access and connection to external hardware
• Reset button
• Automatic switchover between USB and battery power
• CR2032 coin cell holder
UG464: Thunderboard™ EFR32BG22 User's Guide
Introduction
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1.4 Kit Hardware Layout
The layout of the Thunderboard EFR32BG22 is shown below.
Top View Bottom View
Push Button
30.4 mm
45.4 mm
Reset Button
20-pin EXP-header
Breakout Pads
6-axis
Inertial Sensor
USB Micro-B Connector
- Virtual COM port
- Debug access
- Packet trace
Hall Effect
Sensor
Humidity and
Temperature Sensor
Mini Simplicity
Connector
Ambient
Light
Sensor
EFR32BG22
Wireless Gecko
2.4 GHz
Chip Antenna
On-board USB
J-Link Debugger
CR2032 Coin Cell
Holder
Left PDM
Microphone
Right PDM
Microphone
LED
Figure 1.1. Thunderboard EFR32BG22 Hardware Layout
UG464: Thunderboard™ EFR32BG22 User's Guide
Introduction
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2. Specifications
2.1 Recommended Operating Conditions
The following table is intended to serve as guideline for a correct use of Thunderboard EFR32BG22, indicating typical operating condi-
tions and some design limits.
Table 2.1. Recommended Operating Conditions
Parameter Symbol Min Typ Max Unit
USB Supply Input Voltage VUSB — 5.0 — V
Battery Supply Input Voltage VVBAT 2.0 3.0 3.3 V
Supply Input Voltage (VMCU supplied externally)1,2 VVMCU 2.0 3.0 3.6 V
Operating Temperature TOP — 20 — ˚C
Note:
1. The maximum supply voltage may be less under certain conditions when using the EFR32BG22's dc-dc converter. For more in-
formation see the EFR32BG22 data sheet.
2. Not recommended for use with rechargeable Lithium batteries. Most Li-Ion and Li-Po cells exceed 3.6 V when fully charged.
UG464: Thunderboard™ EFR32BG22 User's Guide
Specifications
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2.2 Current Consumption
The table below summarizes the data sheet current consumption of the various components on the board. The operating current of the
board greatly depends on the application. The number of enabled sensors, how often they are sampled and how often the radio is
transmitting or receiving are examples of factors that influence the operating current. In many cases the given conditions differ from the
operating conditions on the Thunderboard EFR32BG22, but the table can still be used as an indication of how much each feature con-
tribute to the total current consumption. More details can be found in the specific data sheet for each device.
Table 2.2. Current Consumption
Parameter Symbol Condition Typ Unit
EFR32BG22 Current Con-
sumption1
IEFR32 MCU current consumption in EM0 mode with all peripher-
als disabled (dc-dc converter at 3.0 V input and 1.8 V out-
put, VSCALE1, 38.4 MHz crystal, CPU running Prime from
flash at 25 ˚C)
28 µA/MHz
EM4, no BURTC, no LF oscillator 0.17 µA
Radio system current consumption in receive mode, active
packet reception (dc-dc converter at 3.0 V input and 1.8 V
output, MCU in EM1 and all MCU peripherals disabled,
HCLK = 38.4 MHz, 1Mbit/s, 2GFSK, f = 2.4 GHz,
VSCALE1 at 25 ˚C)
3.8 mA
Radio system current consumption in transmit mode (dc-
dc converter at 3.0 V input and 1.8 V output, MCU in EM1
and all MCU peripherals disabled, HCLK = 38.4 MHz, f =
2.4 GHz, CW, 6 dBm output power, VSCALE1 at 25 ˚C)
8.4 mA
Ambient Light Sensor Cur-
rent Consumption 2
IVEML6035 Shutdown at 1.8 V 0.5 µA
Operation mode at 1.8 V (ALS only) 170 µA
RH/Temp Sensor Current
Consumption3
ISi7021 Standby, -40 to +85˚C 0.06 µA
RH conversion in progress 150 µA
Temperature conversion in progress 90 µA
Peak IDD during I2C operations 3.5 mA
Hall Effect Magnetic Sensor
Current Consumption 4
IDD Sleep mode at 3.3 V 50 nA
Average current for periodic activation at 3.3 V, sleep tim-
er enabled, 200 msec sleep time
0.4 µA
Conversion in progress at 3.3 V 5 mA
Microphone Current Con-
sumption5
IMIC Sleep mode current (Fclock = 0 Hz, VDD = 3.6 V) 26 µA
Supply current in performance mode (VDD = 3.6 V, Fclock
= 2.4 MHz)
700 µA
IMU Current Consumption6IIMU Full-chip sleep mode at 1.8 V supply 8 µA
Gyroscope Only, 102.3 Hz update rate at 1.8 V supply 1.23 mA
Accelerometer only, 102.3 Hz update rate at 1.8 V supply 68.9 µA
Gyroscope + Accelerometer, 102.3 Hz update rate at 1.8
V supply
1.27 mA
Serial Flash Memory Cur-
rent Consumption 7
IFlash Deep power-down current in ultra low power mode at 1.8
V
0.007 µA
Standby current in ultra low power mode at 1.8 V 5 µA
Write status register current in ultra low power mode at 1.8
V
3.1 mA
UG464: Thunderboard™ EFR32BG22 User's Guide
Specifications
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Parameter Symbol Condition Typ Unit
On-board Debugger Sleep
Current Consumption 8
IDBG On-board debugger current consumption when USB cable
is not inserted (EFM32GG12 EM4S mode current con-
sumption)
80 nA
Minimum Board Current
Consumption
IBOARD Minimum total board current consumption for VMCU = 3.0
V with EFR32BG22 in EM4S, the USB cable disconnec-
ted, and all peripherals either in sleep mode or disconnec-
ted
0.4 µA
Note:
1. From EFM32BG22 data sheet
2. From VEML6035 data sheet
3. From Si7021-A20 data sheet
4. From Si7210 data sheet
5. From SPK0641HT4H-1 data sheet
6. From ICM-20648 data sheet
7. From MX25R8035F data sheet
8. From EFM32GG12 data sheet
UG464: Thunderboard™ EFR32BG22 User's Guide
Specifications
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3. Hardware
The core of the Thunderboard EFR32BG22 is the EFR32BG22 Wireless Gecko System-on-Chip. The board also contains several pe-
ripherals connected to the EFR32BG22. For placement and layout of the hardware components the reader is referred to section 1.4 Kit
Hardware Layout.
3.1 Block Diagram
An overview of the Thunderboard EFR32BG22 is illustrated in the figure below.
Memory
Sensors
Radio
Device Connectivity & Debugging
J-Link
Debugger
USB Micro-B
Connector
2.4 GHz
Antenna
8 Mbit
MX25R
Button and LED
EFR32BG22
Wireless SoC
Breakout Pads
(EXP-Header pinout)
Si7021 Si7210
VEML6035
Temperature
& Humidity
Sensor
Ambient
Light
Sensor
Hall Effect
Sensor
SPK0641HT4H-1 ICM-20648
2x PDM
Microphones
6-axis Inertial
Sensor
User Button
& LED
Mini-Simplicity
Connector
Serial Flash
Figure 3.1. Kit Block Diagram
UG464: Thunderboard™ EFR32BG22 User's Guide
Hardware
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3.2 Power Supply
The kit can be powered through one of these interfaces:
• USB Micro-B
• Battery
• Mini Simplicity connector
The figure below shows the power options available on the kit and illustrates the main system power architecture.
USB Micro-B LDO
5V0
IN OUT
Automatic
Switchover
3V0
VMCU
Battery
EFR32BG22
Wireless SoC
Peripherals
Peripherals
Peripherals
Peripherals
Mini Simplicity
Connector
Figure 3.2. Thunderboard EFR32BG22 Power Architecture
Power is normally applied either through the USB cable or a CR2032 battery. When the USB cable is connected, VBUS is regulated
down to 3.0 V. An automatic switchover circuit switches the main system power from battery power to USB power when the USB cable
is inserted, and protects the battery from reverse current.
Power can also be applied through the Mini Simplicity connector. This requires that no other power sources are present on the kit, as
power is injected directly to the VMCU net. It is important to follow this in order to avoid power conflicts and backfeeding the battery.
Powering the Thunderboard EFR32BG22 through the Mini Simplicity connector allows current measurements using the Advanced En-
ergy Monitoring (AEM) as described in section 4.2 External Debugger.
Important: When powering the board through the Mini Simplicity connector, the USB and battery power sources must be removed.
The power supply options are summarized in the table below.
Table 3.1. Thunderboard EFR32BG22 Power Options
Supply Mode Typical Input Voltage VMCU Source 3V0 5V
USB power 5.0 V On-board regulator On-board regulator USB VBUS
CR2032 battery 3.0 V Battery voltage Disconnected No voltage present
Mini Simplicity 3.3 V Debugger dependent Disconnected No voltage present
3.3 EFR32BG22 Reset
The EFR32BG22 can be reset by a few different sources:
• A user pressing the RESET button.
• The on-board debugger pulling the #RESET pin low.
• An external debugger pulling the #RESET pin low.
UG464: Thunderboard™ EFR32BG22 User's Guide
Hardware
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