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. silabs.com | Smart. Connected. Energy-friendly. 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 silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 1 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 silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 2 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. silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 3 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. silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 4 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. silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 5 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 silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 6 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 silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 7 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 silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 8 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 silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 9 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. silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 10 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. silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 11 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. silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 12 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. silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 13 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. silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 14 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. silabs.com | Smart. Connected. Energy-friendly. Rev. 1.2 | 15 Table of Contents 1. Radio Board Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Radio Board Connector Pin Associations. . . . . . . . . . . . . . . . . . . . . 1 2. System-on-Chip Description 2.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 . . . . . . . . . . . . . . . . . . . . . . . 2 2.2 System-on-Chip Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . 2 2.3 System Summary . . . . . . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . . . 3. Radio Board Block Summary . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.2 Radio Board Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4 4 4 4 5 5 4. RF Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.2 Schematic of the RF Matching Network . . 4.2.1 Description of the 2.4 GHz RF Matching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 . 6 4.3 RF Section Power Supply . . . . . . . . . . . . . . . . . . . 6 4.4 Bill of Materials for the 2.4 GHz Matching . . . . . . . . . . . . . . . . . . . . 6 4.5 Inverted-F Antenna . . . . . . . . . . . . . . . . . . . . . 7 . . . . . . . . . . . . . . . . . . 5. Mechanical Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6. EMC Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7. RF performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 9 9 9 10 7.1 Conducted Power Measurements . . . . . . 7.1.1 Conducted Measurements in the 2.4 GHz band . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 .10 7.2 Radiated Power Measurements . . . . . . 7.2.1 Radiated Measurements in the 2.4 GHz band . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 .11 8. EMC Compliance Recommendations . . . . . . . . . . . . . . . . . . . . . 12 . . 8.1 Recommendations for 2.4 GHz ETSI EN 300-328 compliance . . . . . . . . . . . . .12 Table of Contents 16 8.2 Recommendations for 2.4 GHz FCC 15.247 compliance . . . . . . . . . . . . . . .12 9. Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 10. Board Revisions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 11. Errata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table of Contents 17 Simplicity Studio One-click access to MCU tools, documentation, software, source code libraries & more. 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