RF-Star EFR32MG24 Series User manual

RF-BM-MG24B1/B2
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Shenzhen RF-star Technology Co., Ltd. Page 1 of 21
RF-BM-MG24B1 and RF-BM-MG24B2
EFR32MG24 Series
Multiprotocol 2.4 GHz Wireless Module
Version 1.0
Shenzhen RF-star Technology Co., Ltd.
May 26th, 2023
All rights reserved. Those responsible for unauthorized reproduction will be prosecuted.

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1 Device Overview
1.1 Description
RF-BM-MG24B1 and RF-BM-MG24B2 are IoT wireless connectivity modules based on Silicon Labs EFR32MG24 series
SoCs. They integrate a 39 MHz crystal and a 32.768 kHz crystal, up to 1536 KB programmable flash, and 256 KB RAM
making it possible in many complex applications. Its 32-bit 78 MHz ARM® Cortex®-M33 core can operate at an extremely
low current at flexible power modes. Its multiprotocol 2.4 GHz RF transceiver is compatible with Matter, OpenThread,
Zigbee®, Bluetooth® 5.3 Low Energy, Bluetooth Mesh, and 2.4 GHz Proprietary. It features a small size, robust
connection distance, and rigid reliability. Up to optional 10 dBm or 19.5 dBm TX power enables it in long-range
requirement applications. It features a small size, robust connection distance, and rigid reliability. Those modules are
pin-2-pin compatible with each other.
Table 1. Module Series of RF-BM-MG24Bx
Model
Antenna Output
Mode
Chip Model
Max. CPU
Speed
TX Power
FLASH
RAM
MG24B1
PCB onboard
EFR32MG24A4
10F1536IM48-B
78 MHz
+10 dBm
1536 KB
256 KB
MG24B2
PCB onboard
EFR32MG24A4
20F1536IM48-B
78 MHz
+19.5 dBm
1536 KB
256 KB
1.2 Key Features
•RF Features
- Matter
- OpenThread
- Zigbee®
- Bluetooth® 5.3 Low Energy
- Bluetooth Mesh
- Proprietary 2.4 GHz
•Modulation
- 2-(G)FSK with fully configurable shaping
- OQPSK DSSS
- (G)MSK
•TX power:
- RF-BM-MG24B1: up to +10 dBm
- RF-BM-MG24B1: up to +19.5 dBm
•RF sensitivity
- -105.4 dBm sensitivity @ 250 kbps O-QPSK DSSS
- -105.7 dBm sensitivity @ 125 kbps GFSK
- -97.6 dBm sensitivity @ 1 Mbps GFSK
- -94.8 dBm sensitivity @ 2 Mbps GFSK
•Microcontroller
- Powerful 32-bit 78 MHz ARM® Cortex®-M33 with
DSP instruction and floating-point unit for
efficient signal processing
•Memory
- 1536 KB programmable flash
- 256 KB of RAM
•Support OTA upgrade
•Wide Operation Range
- Power supply:
⬧2.2 V to 3.8 V (DC-DC mode)
⬧1.8 V to 3.8 V (Bypass mode)
- Operating temperature: -40 °C to +85 °C

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- Storage temperature: -40 °C to +125 °C
•Wide Peripherals
- Analog to Digital Converter (IADC)
⬧12-bit @ 1 Msps or 16-bit @ 76.9 ksps
⬧Select OPNs support High Speed Mode
(up to 2 Msps) and High Accuracy Mode
(up to 16 bits ENOB at 3.8 ksps)
- 2 × Analog Comparator (ACMP)
- 2 × Digital to Analog Converter (VDAC)
- Up to 30 General Purpose I/O pins with output
state retention and asynchronous interrupts
- 8 Channel DMA Controller (LDMA)
- 16 Channel Peripheral Reflex System (PRS)
- 3 × 16-bit Timer/Counter with 3
Compare/Capture/PWM channels (TIMER2/3/4)
- 2 × 32-bit Timer/Counter with 3
Compare/Capture/PWM channels (TIMER0/1)
- 2 × 32-bit Real Time Counter
(SYSRTC/BURTC)
- 24-bit Low Energy Timer for waveform
generation (LETIMER)
- 16-bit Pulse Counter with asynchronous
operation (PCNT)
- 2 × Watchdog Timer (WDOG)
- 1 × Universal Synchronous/Asynchronous
Receiver/Transmitter (USART), supporting
UART/SPI/SmartCard (ISO7816)/IrDA/I2S
- 2 × Enhanced Universal
Synchronous/Asynchronous
Receiver/Transmitter (EUSART) supporting
UART/SPI/DALI/IrDA
- 2 × I2C interface with SMBus support
- Low-Frequency RC Oscillator with precision
mode to replace 32 kHz sleep crystal (LFRCO)
- Keypad scanner supporting up to 6x8 matrix
(KEYSCAN)
- Die temperature sensor with +/-1.5 °C accuracy
after singlepoint calibration
•Security Vault
- Hardware Cryptographic Acceleration for
AES128/192/256, ChaCha20-Poly1305, SHA-1,
SHA-2/256/384/512, ECDSA+ECDH(P-192, P-
256, P-384, P-521), Ed25519 and Curve25519,
J-PAKE, PBKDF2
- True Random Number Generator (TRNG) ARM®
TrustZone®
- Secure Boot (Root of Trust Secure Loader)
- Secure Debug Unlock
- DPA Countermeasures
- Secure Key Management with PUF
- Anti-Tamper
- Secure Attestation
•Dimension: 23.35 mm × 17.0 mm × 2.2 mm
1.3 Applications
•Gateway and hubs
•Sensors
•Smark Lighting
•Switches
•Location services
•Wireless healthcare applications
•Asset tracking and management
•Electronic Shelf Label (ESL)

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1.4 Functional Block Diagram
Figure 1. Functional Block Diagram of RF-BM-MG24Bx
1.6 Part Number Conventions
The part numbers are of the form of RF-BM-MG24Bx where the fields are defined as follows:
Figure 2. Part Number Conventions of RF-BM-MG24Bx
RF
BM
MG24
Company Name
RF-STAR
Wireless Type
Bluetooth Module
Chipset
SiliconLabs EFR2MG24 Series
-
-
Bx
Module Version
X： Hardware Version
EFR32MG24
GPIOs
Debug
Reset
Power Supply: 2.2 V ~ 3.8 V (DC-DC mode)
1.8 V ~ 3.8 V (Bypass mode)
Antenna
Matching
39.0 MHz
Matching
PCB Antenna
32.768 kHz

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Table of Contents
1 Device Overview............................................................................................................................................................. 2
1.1 Description............................................................................................................................................................ 2
1.2 Key Features ....................................................................................................................................................... 2
1.3 Applications.......................................................................................................................................................... 3
1.4 Functional Block Diagram .............................................................................................................................. 4
1.6 Part Number Conventions.............................................................................................................................. 4
Table of Contents................................................................................................................................................................ 5
2 Module Configuration and Functions ...................................................................................................................... 6
2.1 Module Parameters........................................................................................................................................... 6
2.2 Module Pin Diagram ......................................................................................................................................... 7
2.3 Pin Functions....................................................................................................................................................... 7
3 Specifications ................................................................................................................................................................... 9
3.1 Recommended Operating Conditions ....................................................................................................... 9
3.2 Handling Ratings................................................................................................................................................ 9
4 Setting of Frequency Offset Register....................................................................................................................10
5 Application, Implementation, and Layout.............................................................................................................11
5.1 Module Photos..................................................................................................................................................11
5.2 Recommended PCB Footprint....................................................................................................................11
5.3 Schematic Diagram.........................................................................................................................................12
5.4 Reference Design............................................................................................................................................13
5.5 Antenna................................................................................................................................................................13
5.5.1 Antenna Design Recommendation ..............................................................................................13
5.6 Basic Operation of Hardware Design ......................................................................................................14
5.7 Trouble Shooting..............................................................................................................................................15
5.7.1 Unsatisfactory Transmission Distance........................................................................................15
5.7.2 Vulnerable Module..............................................................................................................................15
5.7.3 High Bit Error Rate .............................................................................................................................15
5.8 Electrostatics Discharge Warnings ...........................................................................................................16
5.9 Soldering and Reflow Condition.................................................................................................................16
6 Optional Package Specification ..............................................................................................................................18
7 Revision History ............................................................................................................................................................20
8 Contact Us.......................................................................................................................................................................21

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2 Module Configuration and Functions
2.1 Module Parameters
Table 2. Parameters of RF-BM-MG24Bx
Chipset
RF-BM-MG24B1: EFR32MG24A410F1536IM48-B
RF-BM-MG24B2: EFR32MG24A420F1536IM48-B
Supply Power Voltage
2.2 V ~ 3.8 V (DC-DC mode)
1.8 V ~ 3.8 V (Bypass mode)
3.3 V is recommended
Frequency
2400 MHz ～ 2483.5 MHz
Maximum Transmit Power
RF-BM-MG24B1: +10.0 dBm
RF-BM-MG24B2: +19.5 dBm
Receiving Sensitivity
-105.4 dBm sensitivity @ 250 kbps O-QPSK DSSS
-105.7 dBm sensitivity @ 125 kbps GFSK
-97.6 dBm sensitivity @ 1 Mbps GFSK
-94.8 dBm sensitivity @ 2 Mbps GFSK
GPIO
30
Flash
1536 KB
RAM
256 KB
Power Consumption
RX current: 4.4 mA (1 Mbps GFSK)
5.1 mA (250 kbps O-QPSK DSSS)
TX current: 5.0 mA @ 0 dBm
19.1 mA @ 10 dBm
Active Mode (EM0) @ 39.0 MHz: 33.4 μA/MHz
EM2 DeepSleep current (16 kB RAM retention and RTC running from LFRCO):
1.3 μA
Support Protocol
Matter, OpenThread, Zigbee®, Bluetooth® 5.3 Low Energy, Bluetooth Mesh,
Proprietary 2.4 GHz
Crystal
39 MHz, 32.768 kHz
Package
SMT packaging (1.27-mm half-hole pitch stamp stick)
Dimension
23.35 mm × 17.0 mm × 2.2 mm
Type of Antenna
PCB antenna
Operating Temperature
-40 ℃ ～ +85 ℃

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Storage Temperature
-40 ℃ ～ +125 ℃
2.2 Module Pin Diagram
Figure 3. Pin Diagram of RF-BM-MG24Bx
2.3 Pin Functions
Table 3. Pin Functions of RF-BM-MG24Bx
Pin
Name
Chip Pin
Description
1
PB05
PB05
GPIO
2
PB04
PB04
GPIO
3
PB03
PB03
GPIO
4
PB02
PB02
GPIO
5
PB01
PB01
GPIO
6
PB00
PB00
GPIO
7
VREFN
VREFN
Dedicated ADC VREF Negative Input
8
VREFP
VREFP
Dedicated ADC VREF Positive Input
9
PA00
PA00
GPIO

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10
PA03
PA03
GPIO
11
PA04
PA04
GPIO
12
PA05
PA05
GPIO
13
PA06
PA06
GPIO
14
PA07
PA07
GPIO
15
PA08
PA08
GPIO
16
PA09
PA09
GPIO
17
PA02/SWD
PA02/SWD
GPIO/SWD
18
PA01/SWC
PA01/SWC
GPIO/SWC
19
PD05
PD05
GPIO
20
PD04
PD04
GPIO
21
PD03
PD03
GPIO
22
PD02
PD02
GPIO
23
NC
NC
None connect
24
PC00
PC00
GPIO
25
PC01
PC01
GPIO
26
PC02
PC02
GPIO
27
PC03
PC03
GPIO
28
PC04
PC04
GPIO
29
PC05
PC05
GPIO
30
PC06
PC06
GPIO
31
PC07
PC07
GPIO
32
PC08
PC08
GPIO
33
PC09
PC09
GPIO
34
VDD
VDD
Power Supply: 2.2 V ~ 3.8 V (DC-DC mode), 1.8 V ~ 3.8 V (Bypass
mode), recommend to 3.3 V
35
GND
GND
Ground
36
RESET
RESET_N
Reset pin. Active-low. Internal pullup.
In DC-DC mode, the max. pull-low voltage is 1.8 V.

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3 Specifications
3.1 Recommended Operating Conditions
The functional operation does not guarantee performance beyond the limits of the conditional parameter values in the
table below. Long-term work beyond this limit will affect the reliability of the module more or less.
Table 4. Recommended Operating Conditions of RF-BM-MG24Bx
Items
Condition
Min.
Typ.
Max.
Unit
Operating Supply Voltage
DC-DC mode
2.2
3.3
3.8
V
Bypass mode
1.8
3.8
V
Operating Temperature
/
-40
+25
+85
℃
3.2 Handling Ratings
Table 5. Handling Ratings of RF-BM-MG24Bx
Items
Condition
Min.
Typ.
Max.
Unit
Storage Temperature
Tstg
-40
+25
+125
℃
Human Body Model
HBM
±2000
V
Moisture Sensitivity Level
3
Charged Device Model
±500
V

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4 Setting of Frequency Offset Register
Because there is no matching capacitance circuit of the IC’s crystal part, we need to set the frequency offset register
through the software to do the assistant frequency offset adjustment of the hardware RF part.
You can find the sl_device_init_hfxo_config.h file in the corresponding project and modify the CTUNE value.
Take the empty_RGB project as an example:
Find SL_DEVICE_INIT_HFXO_CTUNE, the official default value of SiliconLabs is 140, the value is needed to be
changed to 92 for RF-star’s RF-BM-MG24Bx.
If the user needs to change to other values, you can directly modify it (Value range: 0 ~ 255). As shown below.

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5 Application, Implementation, and Layout
5.1 Module Photos
RF-BM-MG24B1 RF-BM-MG24B2
Figure 4. Photos of RF-BM-MG24Bx
5.2 Recommended PCB Footprint
Figure 5. Recommended PCB Footprint of RF-BM-MG24Bx (mm)

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5.3 Schematic Diagram
Figure 6. Schematic Diagram of RF-BM-MG24Bx

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5.4 Reference Design
Figure 7. Reference Design of RF-BM-MG24Bx
5.5 Antenna
5.5.1 Antenna Design Recommendation
1. The antenna installation structure has a great influence on the module performance. It is necessary to ensure the
antenna is exposed and preferably vertically upward. When the module is installed inside of the case, a high-quality
antenna extension wire can be used to extend the antenna to the outside of the case.
2. The antenna must not be installed inside the metal case, which will cause the transmission distance to be greatly
weakened.
3. The recommendation of antenna layout.
The inverted-F antenna position on PCB is free-space electromagnetic radiation. The location and layout of the
antenna are key factors to increase the data rate and transmission range.
Therefore, the layout of the module antenna location and routing is recommended as follows:
（1）Place the antenna on the edge (corner) of the PCB.
（2）Make sure that there is no signal line or copper foil in each layer below the antenna.

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（3）It is best to hollow out the antenna position in the following figure to ensure that the S11 of the module is
minimally affected.
Figure 8. Recommendation of Antenna Layout
Note: The hollow-out position is based on the antenna used.
5.6 Basic Operation of Hardware Design
1. It is recommended to offer the module a DC stabilized power supply, a tiny power supply ripple coefficient, and
reliable ground. Please pay attention to the correct connection between the positive and negative poles of the power
supply. Otherwise, the reverse connection may cause permanent damage to the module.
2. Please ensure the supply voltage is between the recommended values. The module will be permanently damaged
if the voltage exceeds the maximum value. Please ensure a stable power supply and no frequently fluctuating
voltage.
3. When designing the power supply circuit for the module, it is recommended to reserve more than 30% of the margin,
which is beneficial to the long-term stable operation of the whole machine. The module should be far away from the
power electromagnetic, transformer, high-frequency wiring, and other parts with large electromagnetic interference.
4. The bottom of the module should avoid high-frequency digital routing, high-frequency analog routing, and power
routing. If it has to route the wire on the bottom of the module, for example, it is assumed that the module is soldered
to the Top Layer, the copper must be spread on the connection part of the top layer and the module, and be close
to the digital part of the module and routed in the Bottom Layer (all copper is well-grounded).
5. Assuming that the module is soldered or placed in the Top Layer, it is also wrong to randomly route the Bottom Layer
or other layers, which will affect the spurs and receiving sensitivity of the module to some degree.
6. Assuming that there are devices with large electromagnetic interference around the module, which will greatly affect
the module performance. It is recommended to stay away from the module according to the strength of the
interference. If circumstances permit, appropriate isolation and shielding can be done.
7. Assuming that there are routings of large electromagnetic interference around the module (high-frequency digital,
high-frequency analog, power routings), which will also greatly affect the module performance. It is recommended

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to stay away from the module according to the strength of the interference. If circumstances permit, appropriate
isolation and shielding can be done.
8. It is recommended to stay away from devices whose TTL protocol is the same 2.4 GHz physical layer, for example,
USB 3.0.
5.7 Trouble Shooting
5.7.1 Unsatisfactory Transmission Distance
1. When there is a linear communication obstacle, the communication distance will be correspondingly weakened.
Temperature, humidity, and co-channel interference will lead to an increase in the communication packet loss rate.
The performance of ground absorption and reflection of radio waves will be poor when the module is tested close to
the ground.
2. Seawater has a strong ability to absorb radio waves, so the test results by the seaside are poor.
3. The signal attenuation will be very obvious if there is metal near the antenna or if the module is placed inside the
metal shell.
4. The incorrect power register set or the high data rate in the open air may shorten the communication distance. The
higher the data rate, the closer the distance.
5. The low voltage of the power supply is lower than the recommended value at ambient temperature, and the lower
the voltage, the smaller the power is.
6. The unmatchable antennas and modules or the poor quality of antenna will affect the communication distance.
5.7.2 Vulnerable Module
1. Please ensure the supply voltage is between the recommended values. The module will be permanently damaged
if the voltage exceeds the maximum value. Please ensure a stable power supply and no frequently fluctuating
voltage.
2. Please ensure the anti-static installation and the electrostatic sensitivity of high-frequency devices.
3. Due to some humidity-sensitive components, please ensure the suitable humidity during installation and application.
If there is no special demand, it is not recommended to use at too high or too low temperature.
5.7.3 High Bit Error Rate
1. There are co-channel signal interferences nearby. It is recommended to be away from the interference sources or
modify the frequency and channel to avoid interferences.
2. The unsatisfactory power supply may also cause garbled. It is necessary to ensure the power supply's reliability.
3. If the extension wire or feeder wire is of poor quality or too long, the bit error rate will be high.

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5.8 Electrostatics Discharge Warnings
The module will be damaged by the discharge of static. RF-star suggests that all modules should follow the 3 precautions
below:
1. According to the anti-static measures, bare hands are not allowed to touch modules.
2. Modules must be placed in anti-static areas.
3. Take the anti-static circuitry (when inputting HV or VHF) into consideration in product design.
Static may result in the degradation in performance of the module, even causing failure.
5.9 Soldering and Reflow Condition
1. Heating method: Conventional Convection or IR/convection.
2. Solder paste composition: Sn96.5/Ag3.0/Cu0.5
3. Allowable reflow soldering times: 2 times based on the following reflow soldering profile.
4. Temperature profile: Reflow soldering shall be done according to the following temperature profile.
5. Peak temperature: 245 ℃.
Table 6. Temperature Table of Soldering and Reflow
Profile Feature
Sn-Pb Assembly
Pb-Free Assembly
Solder Paste
Sn63 / Pb37
Sn96.5 / Ag3.0 / Cu0.5
Min. Preheating Temperature (Tmin)
100 ℃
150 ℃
Max. Preheating Temperature (Tmax)
150 ℃
200 ℃
Preheating Time (Tmin to Tmax) (t1)
60 s ~ 120 s
60 s ~ 120 s
Average Ascend Rate (Tmax to Tp)
Max. 3 ℃/s
Max. 3 ℃/s
Liquid Temperature (TL)
183 ℃
217 ℃
Time above Liquidus (tL)
60 s ~ 90 s
30 s ~ 90 s
Peak Temperature (Tp)
220 ℃ ~ 235 ℃
230 ℃ ~ 250 ℃
Average Descend Rate (Tpto Tmax)
Max. 6 ℃/s
Max. 6 ℃/s
Time from 25 ℃ to Peak Temperature (t2)
Max. 6 minutes
Max. 8 minutes
Time of Soldering Zone (tP)
20±10 s
20±10 s

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Figure 9. Recommended Reflow for Lead-Free Solder

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6 Optional Package Specification
The default package method is by tray. If you need the modules to be shipped by tape & reel, pls contact us in advance.
Figure 10. Default Package by Tray

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Figure 11. Package by Tape & Reel

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7 Revision History
Date
Version No.
Description
2023.03.21
V1.0
The initial version is released.
2023.05.26
V1.0
Update the mistake of the pin description.
Update the Shenzhen office address.
Note:
1. The document will be optimized and updated from time to time. Before using this document, please make sure it is
the latest version.
2. To obtain the latest document, please download it from the official website: www.rfstariot.com and www.szrfstar.com.