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9.  Board Revision History

Table 9.1.  BRD4257A Radio Board Revisions

Radio Board Revision

Description

A01

Updating EFR revision to Rev. B.

A00

Initial revision.

Note: 

The silkscreen marking on the board (e.g. PCBxxxx A00) denotes the revision of the PCB. The revision of the actual Radio Board

is laser printed in the 'Board Info' field on the PCB. Also, it can be read from the on-board EEPROM.
 

BRD4257A Reference Manual

Board Revision History

silabs.com

 | Building a more connected world.

Rev. 1.00  |  18

Summary of Contents for BRD4257A

Page 1: ...ures from Expansion Boards With the supporting Simplicity Studio suite of tools developers can take advantage of graphical wireless application develop ment and visual energy profiling and optimization The board also serves as an RF ref erence design for applications targeting 2 4 GHz and 915 MHz dual band wireless oper ation with 19 dBm output power RADIO BOARD FEATURES Wireless SoC EFR32FG14P233...

Page 2: ...ion 8 4 1 Introduction 8 4 2 Schematic of the RF Matching Network 8 4 2 1 Description of the Sub GHz RF Matching 8 4 2 2 Description of the 2 4 GHz RF Matching 8 4 3 RF Section Power Supply 8 4 4 Bill of Materials for the sub GHz Matching 8 4 5 Bill of Materials for the 2 4 GHz Matching 9 4 6 Inverted F Antenna 9 5 Mechanical Details 11 6 EMC Compliance 12 6 1 Introduction 12 6 2 EMC Regulations f...

Page 3: ... 7 2 2 Radiated Measurements in the 2 4 GHz Band 16 8 EMC Compliance Recommendations 17 8 1 Recommendations for 915 MHz FCC 15 247 Compliance 17 8 2 Recommendations for 2 4 GHz ETSI EN 300 328 Compliance 17 8 3 Recommendations for 2 4 GHz FCC 15 247 Compliance 17 9 Board Revision History 18 10 Errata 19 11 Document Revision History 20 silabs com Building a more connected world Rev 1 00 3 ...

Page 4: ...esigned to operate in the US FCC 902 928 MHz band with an external whip antenna the 2 4 GHz section is de signed to operate at the 2400 2483 5 MHz band with the on board printed antenna The matching networks are optimized for operating at 19 dBm output power To develop and or evaluate the EFR32 Flex Gecko the BRD4257A Radio Board can be connected to the Wireless Starter Kit Main board to get acces...

Page 5: ...G F7 PA1 VCOM RX_MISO F5 PA5 VCOM_ENABLE F3 PF3 DEBUG TDI F1 PF0 DEBUG TCK_SWCLK P45 NC P43 NC P41 NC P39 NC P37 PD15 DISP_ENABLE SENSOR_ENABLE F11 PF5 UIF_LED1 F13 PF7 UIF_BUTTON1 F15 PC8 DISP_SCLK F17 PD14 DISP_SCS F19 PB13 PTI SYNC F21 PB11 PTI CLK GND VMCU_IN VCOM CTS_SCLK PA2 P0 P201 Lower Row VCOM RTS_ CS PA3 P2 UIF_BUTTON0 PF6 P4 UIF_BUTTON1 PF7 P6 GND VRF_IN P35 PD15 DISP_ENABLE SENSOR_ENA...

Page 6: ...sceiver with output power up to 19 dBm For additional information on the EFR32FG14P233F256GM48 refer to the EFR32FG14 Data Sheet 3 3 2 LF Crystal Oscillator LFXO The BRD4257A Radio Board has a 32 768 kHz crystal mounted For details regarding the crystal configuration refer to Application Note AN0016 Oscillator Design Considerations 3 3 3 HF Crystal Oscillator HFXO The BRD4257A Radio Board has a 38...

Page 7: ...eries 0 Ohm resistor which is not mounted by default For conducted measure ments 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 2 Description of the 2 4 GHz RF Matching for further details 3 3 8 Radio Board Connectors Two dual row 0 05 pitch polarized connectors make up the BRD4257A Radio Board interface to t...

Page 8: ...formance while in RX mode The matching includes a differential impedance matching circuitry a discrete balanced unbalanced transformer and a filter section The targeted output power is 19 dBm at 915 MHz 4 2 2 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 po...

Page 9: ...ls for the BRD4257A 2 4GHz RF Matching Network Component Name Value Manufacturer Part Number L1 1 8 nH Murata LQP15MN1N8W02D L2 3 0 nH Murata LQP15MN3N0W02D C1 2 0 pF Murata GRM1555C1H2R0WA01D C2 1 0 pF Murata GRM1555C1H1R0WA01D 4 6 Inverted F Antenna The BRD4257A Radio Board includes an on board printed inverted F antenna tuned for the 2 4 GHz band Due to the design restric tions of the Radio Boa...

Page 10: ...re 4 2 Impedance and Reflection of the Inverted F Antenna of the BRD4257A Board Measured from the Matching Output BRD4257A Reference Manual RF Section silabs com Building a more connected world Rev 1 00 10 ...

Page 11: ...d Filter 45 mm 30 mm 38 6 mm 4 4 mm 2 4 GHz Path Selection DC DC Supply Filter Caps Serial Flash DC DC Inductor Figure 5 1 BRD4257A Top View 24 mm 27 3 mm 28 6 mm 5 mm Interface Connector Interface Connector 15 mm Board Identification PAVDD Supply Selection Display Enable Selection WSTK Sensor Enable Selection Figure 5 2 BRD4257A Bottom View BRD4257A Reference Manual Mechanical Details silabs com ...

Page 12: ...mit is 20 dBc based on either conducted or radiated measurement if the emission is not in a restricted band The restricted bands are speci fied 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 which equals to 41 2 dBm in EIRP Additionally for ...

Page 13: ...te balun for details see the schematic of the BRD4257A The transceiver was operated in continuous carrier transmission mode The output power of the radio was set to 19 dBm The typical output spectrum is shown in the following figure Figure 7 1 Typical Output Spectrum of the BRD4257A As shown in the figure the fundamental is close to 19 dBm so it is compliant with the 30 dBm fundamental limit The s...

Page 14: ...perated in continuous carrier transmission mode The output power of the radio was set to 19 dBm The typical output spectrum is shown in the following figure Figure 7 2 Typical Output Spectrum of the BRD4257A As shown in the figure the fundamental is slightly lower than 19 dBm and all of the unwanted emissions are under the 37 6 dBm ap plied limit Note The conducted measurement is performed by conn...

Page 15: ...anes are illustrated in the figure below Figure 7 3 Illustration of Reference Planes with a Radio Board Plugged into the Wireless Starter Kit Mainboard Note The radiated measurement results presented in this document were recorded in an unlicensed antenna chamber Also the radi ated power levels may change depending on the actual application PCB size used antenna and so on Therefore the absolute le...

Page 16: ...9 dB the harmonic levels are also compliant 7 2 2 Radiated Measurements in the 2 4 GHz Band For the transmitter antenna the on board printed inverted F antenna of the BRD4257A Radio Board was used the R1 resistor was mounted The supply for the RF section RFVDD was 1 8 V provided by the on chip DCDC converter the supply for the 2 4 GHz power amplifier PAVDD was 3 3 V provided by the mainboard for d...

Page 17: ... due to the high antenna gain In order to be compliant reduction of the fundamental power is required by approximately 2 4 dB The harmonic emissions are under the 30 dBm limit with a large margin Although the BRD4257A Radio Board has an option for mounting a shielding can it is not required for the compliance 8 3 Recommendations for 2 4 GHz FCC 15 247 Compliance As it was shown in the previous cha...

Page 18: ...tial revision Note The silkscreen marking on the board e g PCBxxxx A00 denotes the revision of the PCB The revision of the actual Radio Board is laser printed in the Board Info field on the PCB Also it can be read from the on board EEPROM BRD4257A Reference Manual Board Revision History silabs com Building a more connected world Rev 1 00 18 ...

Page 19: ...10 Errata There are no known errata at present BRD4257A Reference Manual Errata silabs com Building a more connected world Rev 1 00 19 ...

Page 20: ...11 Document Revision History Revision 1 00 2017 10 26 Initial document revision BRD4257A Reference Manual Document Revision History silabs com Building a more connected world Rev 1 00 20 ...

Page 21: ...mply or express copyright licenses granted hereunder to design or fabricate any integrated circuits The products are not designed or authorized to be used within any Life Support System without the specific written consent of Silicon Labs A Life Support System is any product or system intended to support or sustain life and or health which if it fails can be reasonably expected to result in signif...

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