BRD4252A Reference Manual: EFR32FG 2.4 GHz, 19.5 dBm Radio Board

BRD4252A Reference Manual
EFR32FG 2.4 GHz 19.5 dBm Radio Board
The EFR32FG family of Wireless SoCs deliver a high performance, low energy wireless solution integrated into a small form
factor package.
By combining a high performance 2.4 GHz RF transceiver with an energy efficient 32-bit
MCU, the family provides designers the ultimate in flexibility with a family of pin-compatible devices that scale from 32/64/128/256 kB of flash and 8/16/32 kB of RAM. The ultralow power operating modes and fast wake-up times of the Silicon Labs energy friendly
32-bit MCUs, combined with the low transmit and receive power consumption of the 2.4
GHz radio, result in a solution optimized for battery powered applications.
To develop and/or evaluate the EFR32 Flex Gecko the EFR32FG Radio Board can be
connected to the Wireless Starter Kit Mainboard to get access to display, buttons and
additional features from Expansion Boards.
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RADIO BOARD FEATURES
• Wireless SoC:
EFR32FG1P132F256GM48-B0
• CPU core: ARM Cortex-M4 with FPU
• Flash memory: 256 kB
• RAM: 32 kB
• Operation frequency: 2.4 GHz
• Transmit power: 19.5 dBm
• Integrated PCB antenna, UFL connector
(optional).
• Crystals for LFXO and HFXO: 32.768 kHz
and 38.4 MHz.
Rev. 1.2
EFR32FG 2.4 GHz 19.5 dBm Radio Board
Radio Board Connector
1. Radio Board Connector
1.1 Introduction
The board-to-board connector scheme allows access to all EFR32FG1 GPIO pins as well as the RESETn signal. For more information
on the functions of the available pin functions, we refer you to the EFR32FG1 Datasheet.
1.2 Radio Board Connector Pin Associations
The figure below shows the pin mapping on the connector to the radio pins, and their function on the Wireless Starter Kit Mainboard.
P200
Upper Row
3v3
UIF_BUTTON1 / PF7 / P36
NC / P38
NC / P40
NC / P42
NC / P44
DEBUG.TMS_SWDIO / PF1 / F0
DEBUG.TDO_SWO / PF2 / F2
NC / P4
VCOM.TX_MOSI / PA0 / F6
VCOM.#CTS_SCLK / PA2 / F8
DISP_EXTCOMIN / PD13 / F10
UIF_BUTTON0 / PF6 / F12
DISP_ENABLE / PD15 / F14
DISP_SI / PC6 / F16
DISP_EXTCOMIN / PD13 / F18
PTI.DATA / PB12 / F20
USB_VBUS
5V
Board ID SCL
P201
Lower Row
GND
GND
VCOM.#CTS_SCLK / PA2 / P0
P37 / High / SENSOR_ENABLE
VCOM.#RTS_#CS / PA3 / P2
P39 / NC
PD10 / P4
P41 / NC
PD11 / P6
P43 / NC
PD12 / P8
P45 / NC
DEBUG.TDI / PF3 / P10
F1 / PF0 / DEBUG.TCK_SWCLK
PC10 / P12
F3 / PF3 / DEBUG.TDI
PA4 / P14
F5 / PA5 / VCOM_ENABLE
VCOM_ENABLE / PA5 / P16
F7 / PA1 / VCOM.RX_MISO
PTI.CLK / PB11 / P18
F9 / PA3 / VCOM.#RTS_#CS
PTI.DATA / PB12 / P20
F11 / PF5 / UIF_LED1
PTI.SYNC / PB13 / P22
F13 / PF7 / UIF_BUTTON1
DEBUG.TCK_SWCLK / PF0 / P24
F15 / PC8 / DISP_SCLK
DEBUG.TMS_SWDIO / PF1 / P26
F17 / PD14 / DISP_SCS
DEBUG.TDO_SWO / PF2 / P28
F19 / PB13 / PTI.SYNC
UIF_LED0 / PF4 / P30
F21 / PB11 / PTI.CLK
UIF_LED1 / PF5 / P32
USB_VREG
UIF_BUTTON0 / PF6 / P34
GND
GND
Board ID SDA
VMCU_IN
P1 / PC6 / DISP_SI
P3 / PC7
P5 / PC8 / DISP_SCLK
P7 / PC9
P9 / PA0 / VCOM.TX_MOSI
P11 / PA1 / VCOM.RX_MISO
P13 / PC11
P15 / NC
P17 / NC
P19 / NC
P21 / NC
P23 / NC
P25 / NC
P27 / NC
P29 / NC
P31 / PD13 / DISP_EXTCOMIN
P33 / PD14 / DISP_SCS
P35 / PD15 / DISP_ENABLE
VRF_IN
Figure 1.1 BRD4252A Radio Board Connector Pin Mapping
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EFR32FG 2.4 GHz 19.5 dBm Radio Board
System-on-Chip Description
2. System-on-Chip Description
2.1 Introduction
The EFR32 product family features the world’s most energy friendly System-on-Chip radios. The devices are well suited for any battery
operated application as well as other systems requiring high performance and low-energy consumption. This section gives a short introduction to the full radio and MCU system.
2.2 System-on-Chip Block Diagram
The block diagram of the EFR32FG1 is shown in the figure below.
Core / Memory
ARM CortexTM M4 processor
with DSP extensions and FPU
Flash Program
Memory
Clock Management
Memory
Protection Unit
RAM Memory
DMA Controlller
Debug Interface
Energy Management
Other
High Frequency
Crystal Oscillator
High Frequency
RC Oscillator
Voltage
Regulators
Voltage Monitor
CRYPTO
Low Frequency
RC Oscillator
Auxiliary High
Frequency RC
Oscillator
DC/DC Regulator
Power-On Reset
CRC
Low Frequency
Crystal Oscillator
Ultra Low
Frequency RC
Oscillator
Brown-Out
Detector
32-bit bus
Peripheral Reflex System
RFSENSE
FRC
DEMOD
LNA
PGA
IFADC
Serial I/F
I/O Ports
USART
External
Interrupts
Timer/Counter
Protocol Timer
ADC
Low Energy
UARTTM
General
Purpose I/O
Low Energy
Timer
Watchdog Timer
Analog
Comparator
I2C
Pin Reset
Pulse Counter
Real Time
Counter and
Calendar
IDAC
Timers and Triggers
RF Frontend
Q
AGC
Frequency
Synthesizer
RAC
PA
CRC
BALUN
I
BUFC
Radio Transceiver
MOD
Pin Wakeup
Analog I/F
Cryotimer
Lowest power mode with peripheral operational:
EM0—Active
EM1—Sleep
EM2—Deep Sleep
EM3—Stop
EM4—Hibernate
EM4—Shutoff
Figure 2.1 EFR32FG1 Block Diagram
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EFR32FG 2.4 GHz 19.5 dBm Radio Board
System-on-Chip Description
2.3 System Summary
The EFR32FG1 has the following main features:
• Supports single-band operation in the 2.4 GHz band.
• Cortex-M4 with FPU processor including a 32-bit RISC processor, also equipped with DSP instruction support and a floating-point
unit.
• Supports two crystal oscillators and fully integrates four RC oscillators.
• Contains a high performance, low phase noise, fully integrated fractional-N frequency synthesizer.
• Wake on Radio feature: allows flexible, autonomous RF sensing, qualification, and demodulation without required MCU activity.
• RFSENSE module: generates a system wakeup interrupt upon detection of wideband RF energy at the antenna interface, providing
true RF wakeup capabilities from low energy modes.
• Has an extensive and flexible frame handling support for easy implementation of even complex communication protocols.
• Frame Controller (FRC) with a packet and state trace unit.
• Advanced buffer controller (BUFC) capable of handling up to 4 buffers of adjustable size.
• Radio Controller (RAC): controls the top level state of the radio subsystem.
• Crypto Accelerator (CRYPTO): fast and energy-efficient autonomous hardware accelerator for AES encryption and decryption.
• Highly efficient integrated regulators for generating internal supply voltages.
• Peripheral Reflex System (PRS): provides a communication network between different peripheral modules without software involvement.
• Serial Communication Interfaces:
• Universal Synchronous/Asynchronous Receiver/Transmitter (USART)
• Low Energy Universal Asynchronous Receiver/Transmitter (LEUART).
• Inter-Integrated Circuit Interface (I2C).
• Analog Interfaces:
• The ADC is a Successive Approximation Register architecture, with a resolution of up to 12 bits at up to 1 MSamples/s.
• Analog Comparator (ACMP).
• The Digital to Analog Current Converter (IDAC) can source or sink a configurable constant current.
• The Analog Port (APORT) Interconnect is a centralized channel switch matrix shared between ADC, ACMP, and IDAC.
• Various Timers and Triggers:
• Timer/Counter: keep track of timing, count events, generate PWM outputs and trigger timed actions in other peripherals through
the PRS system.
• Real Time Counter and Calendar: 32-bit counter providing timekeeping in all energy modes.
• Low Energy Timer: allows it to be used for timing and output generation when most of the device is powered down, allowing simple tasks to be performed while the power consumption of the system is kept at an absolute minimum.
• Ultra Low Power Wake-up Timer (CRYOTIMER): can provide periodic Wakeup events and PRS signals which can be used to
wake up peripherals from any energy mode.
• The Pulse Counter (PCNT) peripheral can be used for counting pulses on a single input or to decode quadrature encoded inputs.
• Watchdog Timer.
• The device has 31 General Purpose Input/Output (GPIO) pins
• Integrated DC-DC buck converter covers a wide range of load currents and provides high efficiency in energy modes EM0, EM1,
EM2 and EM3. Patented RF noise mitigation allows operation of the DC-DC converter without degrading radio sensitivity.
The detailed functional descriptions can be found in the EFR32FG1 Data Sheet and EFR32 Reference Manual.
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EFR32FG 2.4 GHz 19.5 dBm Radio Board
Radio Board Block Summary
3. Radio Board Block Summary
3.1 Introduction
This section gives a short introduction to the blocks of the BRD4252A Radio Board.
3.2 Radio Board Block Diagram
The block diagram of the EFR32FG Radio Board is shown in the figure below.
I2C
UFL
Connector
2.4 GHz RF
GPIO
UART
Debug
AEM
EFR32
Packet Trace
Matching
Network &
Path
Selection
2.4 GHz RF
Inverted-F
PCB Antenna
SPI
SPI
I2C
Radio
Board
Connectors
2.4 GHz RF
8k
32
24AA0024
8 Mbit
MX25R
Serial EEPROM
Serial Flash
.76
LF
Crystal
.4M
38
HF
Crystal
Figure 3.1 BRD4252A Block Diagram
3.3 Radio Board Block Description
3.3.1 LF Crystal Oscillator (LFXO)
The BRD4252A Radio Board has a 32.768 kHz crystal mounted (P/N: CM8V-T1A, 32768Hz, 12.5pF, +/- 20ppm).
3.3.2 HF Crystal Oscillator (HFXO)
The BRD4252A Radio Board has a 38.4 MHz crystal mounted (P/N: DSX211SH 38.4 MHz 1ZZNAE38400AB0A).
3.3.3 Matching Network for 2.4 GHz
The BRD4252A Radio Board incorporates a 2.4 GHz matching network which connects the 2.4 GHz TRX pin of the EFR32FG1 to the
one on-board printed Inverted-F antenna. The component values were optimized for the 2.4 GHz band RF performace and current consumption with 19.5 dBm output power.
For detailed description of the matching network see Chapter 4.2.1 Description of the 2.4 GHz RF Matching.
3.3.4 Inverted-F Antenna
The BRD4252A Radio Board includes a printed Inverted-F antenna (IFA) tuned to have close to 50 Ohm impedance at the 2.4 GHz
band.
For detailed description of the antenna see Chapter 4.5 Inverted-F Antenna.
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EFR32FG 2.4 GHz 19.5 dBm Radio Board
Radio Board Block Summary
3.3.5 UFL Connector
To be able to perform conducted measurements Silicon Labs added an UFL connector (P/N: U.FL-R-SMT-1) to the Radio Board. The
connector allows an external 50 Ohm cable or antenna to be connected during design verification or testing.
Note: By default the output of the matching network is connected to the printed Inverted-F antenna by a series component. It can be
connected to the UFL connector as well through a series 0 Ohm resistor which is not mounted by default. For conducted measurements
through the UFL connector the series component to the antenna should be removed and the 0 Ohm resistor should be mounted (see
Chapter 4.2 Schematic of the RF Matching Network for further details).
3.3.6 Radio Board Connector
Two dual-row, 0.05” pitch polarized connectors (P/N: SFC-120-T2-L-D-A-K-TR) make up the EFR32FG Radio Board interface to the
Wireless Starter Kit Mainboard.
For more information on the pin mapping between the EFR32FG1P132F256GM48-B0 and the Radio Board Connector refer to Chapter
1. Radio Board Connector.
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EFR32FG
EFR32FG 2.4 GHz 19.5 dBm Radio Board
RF Section
4. RF Section
4.1 Introduction
This section gives a short introduction to the RF section of the BRD4252A.
4.2 Schematic of the RF Matching Network
The schematic of the RF section of the BRD4252A Radio Board is shown in the following figure.
U1B
RF Crystal
10
HFXTAL_N
HFXI
Path
Selection &
Harmonic
Suppression
2.4 GHz
Matching
Network
L2
L1
RF I/O
2G4RF_IOP
Inverted-F
Antenna
AT1
C3
17
C1
C2
INVERTED_F
Supply
Filtering
RFVDD
L102
11
HFXTAL_P
HFXO
RF Analog Power
1
2
BLM18AG601SN1
9
C102
C103
100P
10P
PAVDD
2G4RF_ION
R2
0R
NM
Ground
RFVDD
RFVSS
L103
16
14
GND
P1
3
PA Power
1
2
BLM18AG601SN1
18
C106
220N
GND
PAVDD
PAVSS
15
1
2
C107
U.FL
10P
GND
Test
Connector
GND
GND
Figure 4.1 Schematic of the RF Section of the BRD4252A
4.2.1 Description of the 2.4 GHz RF Matching
The 2.4 GHz matching connects the 2G4RF_IOP pin to the on-board printed Inverted-F Antenna. The 2G4RF_ION pin is connected to
ground. For higher output powers (13 dBm and above) beside the impedance matching circuitry it is recommended to use additional
harmonic filtering as well at the RF output. The targeted output power of the BRD4252A board is 19.5 dBm thus the RF output of the IC
is connected to the antenna through a four-element impedance matching and harmonic filter circuitry.
For conducted measurements the output of the matching network can also be connected to the UFL connector by removing the series
C3 capacitor between the antenna and the output of the matching and adding a 0 Ohm resistor to the R2 resistor position between the
output of the matching and the UFL connector.
4.3 RF Section Power Supply
On the BRD4252A Radio Board the supply pin of the RF Analog Power (RFVDD) is connected directly ot the output of the on-chip DCDC converter while the supply for the 2.4 GHz PA (PAVDD) is provided directly by the mainboard. This way, by default, the DC-DC
converter provides 1.8 V for the RF analog section, the mainboard provides 3.3 V for the PA (for details, see the schematic of the
BRD4252A).
4.4 Bill of Materials for the 2.4 GHz Matching
The Bill of Materials of the 2.4 GHz matching network of the BRD4252A Radio Board is shown in the following table.
Table 4.1. Bill of Materials for the BRD4252A 2.4 GHz 19.5 dBm RF matching network
Component name
Value
Part Number
L1
1.8 nH
LQP15MN1N8W02
L2
3.0 nH
LQP15MN3N0W00
C1
2.0 pF
GRM1555C1H2R0WA01
C2
1.0 pF
GRM1555C1H1R0WA01
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EFR32FG 2.4 GHz 19.5 dBm Radio Board
RF Section
4.5 Inverted-F Antenna
The BRD4252A Radio Board includes an on-board printed Inverted-F Antenna tuned for the 2.4 GHz band. Due to the design restrictions of the Radio Board the input of the antenna and the output of the matching network can't be placed directly next to each other thus
a 50 Ohm transmission line was necessary to connect them. With the actual line length the impedance of the antenna at the doubleharmonic frequency is transformed closer to a "critical load impedance range" thus the radiated level of the harmonic increases.
To reduce the harmonic radiation a tuning component was used instead of a series 0 Ohm resistor between the matching network output and the antenna input. For the actual Radio Board design (with the actual transmission line length) a small value capacitor was
used (C3 capacitor with value of 3.9 pF) to transform the impedance at the double-frequency harmonic away from the critical region
while keeping the impedance at the fundamental close to 50 Ohm. With this the suppression of the radiated double-frequency harmonic
increases by approx. 5 dB. The resulting impedance and reflection are shown in the following figure.
Figure 4.2 Impedance and Reflection of the Inverted-F Antenna of the BRD4252A
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EFR32FG 2.4 GHz 19.5 dBm Radio Board
Mechanical Details
5. Mechanical Details
The EFR32 Flex Gecko Radio Board (BRD4252A) is illustrated in the figures below.
DC-DC
Inductor
DC-DC
&
Supply
Filter
Caps.
EFR32xx
30 mm
OTA
Flash Frame of
the
Optional
Shielding
Can
43 mm
Figure 5.1 BRD4252A Top View
24 mm
5 mm
Board
Identification
P 200
P 201
27.3 mm
28.6 mm
15 mm
Interface
Connector
Interface
Connector
Figure 5.2 BRD4252A Bottom View
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EFR32FG 2.4 GHz 19.5 dBm Radio Board
EMC Compliance
6. EMC Compliance
6.1 Introduction
Compliance of the fundamental and harmonic levels is tested against the following standards:
• 2.4 GHz:
• ETSI EN 300-328
• FCC 15.247
6.2 EMC Regulations for 2.4 GHz
6.2.1 ETSI EN 300-328 Emission Limits for the 2400-2483.5 MHz Band
Based on ETSI EN 300-328 the allowed maximum fundamental power for the 2400-2483.5 MHz band is +20 dBm EIRP. For the unwanted emissions in the 1 GHz to 12.75 GHz domanin the specified limit is -30 dBm EIRP.
6.2.2 FCC15.247 Emission Limits for the 2400-2483.5 MHz Band
FCC 15.247 allows conducted output power up to 1 Watt (+30 dBm) in the 2400-2483.5 MHz band. For spurious emmissions the limit is
-20 dBc based on either conducted or radiated measurement, if the emission is not in a restricted band. The restricted bands are specified in FCC 15.205. In these bands the spurious emission levels must meet the levels set out in FCC 15.209. In the range from 960
MHz to the frequency of the 5th harmonic it is defined as 0.5 mV/m at 3 m distance (equals to -41.2 dBm in EIRP).
Additionally, for spurious frequencies above 1 GHz FCC 15.35 allows duty-cycle relaxation to the regulatory limits. For the EmberZNet
PRO the relaxation is 3.6 dB. So practically the -41.2 dBm limit can be modified to -37.6 dBm.
In case of operating in the 2400-2483.5 MHz band the 2nd, 3rd and 5th harmonics can fall into restricted bands so for those the -37.6
dBm limit should be applied. For the 4th harmonic the -20 dBc limit should be applied.
6.2.3 Applied Emission Limits for the 2.4 GHz Band
The above ETSI limits are applied both for conducted and radiated measurements.
The FCC restricted band limits are radiated limits only. Besides that, Silicon Labs applies those to the conducted spectrum i.e. it is assumed that in case of a custom board an antenna is used which has 0 dB gain at the fundamental and the harmonic frequencies. In that
theoretical case, based on the conducted measurement, the compliance with the radiated limits can be estimated.
The overall applied limits are shown in the table below.
Table 6.1. Applied limits for spurious emissions for the 2.4 GHz band
Harmonic
Frequency
Limit
2nd
4800~4967 MHz
-37.6 dBm
3rd
7200~7450.5 MHz
-37.6 dBm
4th
9600~9934 MHz
-30 dBm
5th
12000~12417.5 MHz
-37.6 dBm
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EFR32FG 2.4 GHz 19.5 dBm Radio Board
RF performance
7. RF performance
7.1 Conducted Power Measurements
7.1.1 Conducted Measurements in the 2.4 GHz band
The BRD4252A board was connected directly to a Spectrum Analyzer through its UFL connector (the C3 capacitor was removed and a
0 Ohm resistor was soldered to the R2 resistor position). During the measurements the voltage supply for the board was 3.3 V provided
by the mainboard. The supply for the RF section was 1.8 V provided by the on-chip DC-DC converter (for details, see the schematic of
the BRD4252A). The transceiver was operated in continuous carrier transmission mode. The output power of the radio was set to 19.5
dBm.
The typical output spectrum is shown in the following figure.
Figure 7.1 Typical Output Spectrum of the BRD4252A
As it can be observed the fundamental is slightly lower than 19.5 dBm limit and the strongest unwanted emission is the double-frequency harmonic and it is under the -37.6 dBm applied limit.
Note: The conducted measurement is performed by connecting the on-board UFL connector to a Spectrum Analyzer through an SMA
Conversion Adapter (P/N: HRMJ-U.FLP(40)). This connection itself introduces approx. 0.3 dB insertion loss.
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EFR32FG 2.4 GHz 19.5 dBm Radio Board
RF performance
7.2 Radiated Power Measurements
During measurements the EFR32 Flex Gecko Radio Board (BRD4252A) was attached to a Wireless Starter Kit Mainboard (BRD4001
(Rev. A02) ). The radiated power was measured in an antenna chamber by rotating the DUT in 360 degree with horizontal and vertical
reference antenna polarizations in the XY, XZ and YZ cuts. The measurement axes are as shown in the figure below.
Figure 7.2 DUT: Radio Board with the Wireless Starter Kit Mainboard (Illustration)
Note: The radiated measurement results presented in this document were recorded in an unlicensed antenna chamber. Also the radiated power levels may change depending on the actual application (PCB size, used antenna etc.) therefore the absolute levels and
margins of the final application is recommended to be verified in a licensed EMC testhouse!
7.2.1 Radiated Measurements in the 2.4 GHz band
For the transmitter antenna the on-board printed Inverted-F antenna of the BRD4252A board was used (the C3 capacitor was mounted). During the measurements the board was attached to a Wireless Starter Kit Mainboard (BRD4001 (Rev. A02) ) which was supplied
through USB. During the measurements the voltage supply for the board was 3.3 V provided by the mainboard. The supply for the RF
section was 1.8 V provided by the on-chip DC-DC converter (for details, see the schematic of the BRD4252A). The transceiver was
operated in continuous carrier transmission mode. The output power of the radio was set based to 19.5 dBm based on the conducted
measurement.
The results are shown in the table below.
Table 7.1. Maximums of the measured radiated powers of BRD4252A
2.4 GHz
EIRP [dBm]
Orientation
Margin [dB]
Limit in EIRP [dBm]
Fund
22
XZ/H
8
30
2nd
-42.1
XZ/H
4.5
-37.6
3rd
-55.1
YZ/H
17.5
-37.6
4th
Noise*
-/-
>20
-30
5th
Noise*
-/-
>10
-37.6
* Signal level is below the Spectrum Analyzer noise floor.
As it can be observed, thanks to the high gain of the Inverted-F antenna, the level of the fundamental is higher than 19.5 dBm. The
strongest harmonic is the double-frequency one and thanks to the additional suppression provided by the C3 capacitor its level is only
around -50 dBm.
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EFR32FG 2.4 GHz 19.5 dBm Radio Board
EMC Compliance Recommendations
8. EMC Compliance Recommendations
8.1 Recommendations for 2.4 GHz ETSI EN 300-328 compliance
As it was shown in the previous chapter the radiated power of the fundamental of the EFR32 Flex Gecko Radio Board (BRD4252A)
complies with the 20 dBm limit of the ETSI EN 300-328 both in case of the conducted and the radiated measurements. The harmonic
emissions are under the -30 dBm limit. Although the BRD4252A Radio Board has an option for mounting a shielding can (P/N: Frame:
BMI-S-203-F; Cover: BMI-S-203-C) that is not required for the compliance.
8.2 Recommendations for 2.4 GHz FCC 15.247 compliance
As it was shown in the previous chapter the radiated power of the fundamental of the EFR32 Flex Gecko Radio Board (BRD4252A)
complies with the 30 dBm limit of the FCC 15.247. The harmonic emissions are under the -37.6 dBm applied limit both in case of the
conducted and the radiated measurements. Although the BRD4252A Radio Board has an option for mounting a shielding can (P/N:
Frame: BMI-S-203-F; Cover: BMI-S-203-C) that is not required for the compliance.
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EFR32FG 2.4 GHz 19.5 dBm Radio Board
Revision History
9. Revision History
Table 9.1. Document Revision History
Revision Number
Effective Date
Change Description
1.0
27.11.2015
Initial release.
1.1
28.01.2016
Fixing image render problem.
1.2
11.02.2016
Adding RF Section Power Supply chapter. Minor improvements.
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EFR32FG 2.4 GHz 19.5 dBm Radio Board
Board Revisions
10. Board Revisions
Table 10.1. BRD4252A Radio Board Revisions
Radio Board Revision
Description
A01
Initial release
Note: The silkscreen marking on the board (e.g. PCBxxxx A00) denotes the revision of the PCB. The revision of the actual Radio Board
can be read from the on-board EEPROM.
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EFR32FG 2.4 GHz 19.5 dBm Radio Board
Errata
11. Errata
Table 11.1. BRD4252A Radio Board Errata
Radio Board Revision
Problem
Description
A01
Incorrect silkscreen
marking.
Output power marked as "20 dBm" instead of "19.5 dBm."
Unnecessary component Power Amplifier settings have been optimized so the C3 capacitor is not necesmounted.
sary any more, 0 Ohm resistor can be used instead.
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Table of Contents
1. Radio Board Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Introduction.
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2. System-on-Chip Description
2.1 Introduction.
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. 2
2.2 System-on-Chip Block Diagram .
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. 2
2.3 System Summary
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3. Radio Board Block Summary . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1 Introduction.
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. 4
3.2 Radio Board Block Diagram .
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. 4
3.3 Radio Board Block Description .
3.3.1 LF Crystal Oscillator (LFXO) .
3.3.2 HF Crystal Oscillator (HFXO) .
3.3.3 Matching Network for 2.4 GHz.
3.3.4 Inverted-F Antenna . . . .
3.3.5 UFL Connector . . . . . .
3.3.6 Radio Board Connector . . .
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4. RF Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1 Introduction.
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4.2 Schematic of the RF Matching Network . .
4.2.1 Description of the 2.4 GHz RF Matching .
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. 6
. 6
4.3 RF Section Power Supply .
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. 6
4.4 Bill of Materials for the 2.4 GHz Matching
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. 6
4.5 Inverted-F Antenna .
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. 7
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5. Mechanical Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6. EMC Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.1 Introduction.
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. 9
6.2 EMC Regulations for 2.4 GHz . . . . . . . . . . . . .
6.2.1 ETSI EN 300-328 Emission Limits for the 2400-2483.5 MHz Band
6.2.2 FCC15.247 Emission Limits for the 2400-2483.5 MHz Band. . .
6.2.3 Applied Emission Limits for the 2.4 GHz Band . . . . . . .
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7. RF performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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7.1 Conducted Power Measurements . . . . . .
7.1.1 Conducted Measurements in the 2.4 GHz band .
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.10
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7.2 Radiated Power Measurements . . . . . .
7.2.1 Radiated Measurements in the 2.4 GHz band
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.11
8. EMC Compliance Recommendations . . . . . . . . . . . . . . . . . . . . .
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8.1 Recommendations for 2.4 GHz ETSI EN 300-328 compliance
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.12
Table of Contents
16
8.2 Recommendations for 2.4 GHz FCC 15.247 compliance
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.12
9. Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13
10. Board Revisions. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14
11. Errata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15
Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16
Table of Contents
17
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