Silicon Laboratories SI4421 Si4421 REFERENCE DESIGNS, Schematics, Recommended Component Types

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Si4421

Si4421

REFERENCE DESIGNS

Evaluation Board with 50 Ohm Matching Network

Schematics

CN61

1DCLK

2SDI

3

4DATA

5SEL

6SDO

7

8SCK

9IRQ

10ARSSI

11VDI

12RESET

13

14

GND

VDD

		VDD
C3 *	C2	C1
	10nF	2.2uF

IC1

SDI	1	SDI	NINT/VDI
SCK	2	SCK	ARSSI
SEL	3	NSEL	VDD
SDO	4	SDO	RF1
IRQ	5	NIRQ	RF2
DATA	6	FSK/DATA/NFFS VSS
DCLK	7	DCLK/CFIL/FFIT NRES
	8	CLK	XTL/REF
		CLK	XTL/REF

IA4421

OUT_CLK

C4	4.7nF ARSSI

GND

16VDI

15	ARSSI	VDD
15	ARSSI
14
13
12		GND
11		GND
11

10RESET

9

Q61

10MHz

GND

MATCHING_NETWORK		C8*
MATCHING_NETWORK
*			GND
*			GND
L1			GND
L1
C10	*
	*
	L2
*	GND
*	GND
L4	GND
L4
	C9*	C11 *	CN62
		optional	ANT
*			GND
*
L3
	* See values in the table
VDD

GND

Frequency Dependent Component Values

VDD

f [MHz]	L1 [nH]	L2 [nH]	L3 [nH]	L4 [nH]	C8 [pF]	C9 [pF]	C10 [pF]	C11 [pF]	C3 [pF]
434	18	47	390	18	5	2.7	2.7	220	220
868	3.9	18	100	3.9	2.7	1.2	1.8	47	47
915	3.6	16	100	3.6	2.7	1.2	1.8	33	33

Recommended Component Types

	Component		Manufacturer				Part number				Note
	Component		Manufacturer								Note
					434MHz		868 MHz		915MHz

	L1		Coilcraft		0603CS-18NX		0603CS-3N9X		0603CS-3N9X	1
	L4		Coilcraft		0603CS-18NX		0603CS-3N9X		0603CS-3N9X	1
	L2		Coilcraft		0603CS-47NX		0603CS-18NX		0603CS-16NX	1
	L3		Coilcraft		0603CS-R39X		0603CS-R10X		0603CS-R10X	2
	C9		Murata		GRM1885C1H2R7CZ01B		GRM1885C1H1R2CZ01B		GRM1885C1H1R2CZ01B	3
	C8		Murata		GRM1885C1H5R0CZ01B		GRM1885C1H2R7CZ01B		GRM1885C1H2R7CZ01B	3
	C10		Murata		GRM1885C1H2R7CZ01B		GRM1885C1H1R8CZ01B		GRM1885C1H1R8CZ01B	3, 4
	C11		Murata		GRM1885C1H221JA01B		GRM1885C1H470JZ01B		GRM1885C1H330JZ01B	3
	C3		Murata		GRM1885C1H221JA01B		GRM1885C1H470JZ01B		GRM1885C1H330JZ01B	3

For component selection guidelines, see the notes on the next page.

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Contents TYPICAL APPLICATIONS FUNCTIONAL BLOCK DIAGRAMFEATURES DESCRIPTIONSi4421 DETAILED FEATURE-LEVELDESCRIPTIONRF Power Amplifier PA Data Filtering and Clock RecoveryCrystal Oscillator Low Battery Voltage DetectorWake-UpTimer Data Validity BlocksFunction Si4421 PACKAGE PIN DEFINITIONSName TypeInternal connection Si4421Internal Pin Connections NameSi4421 PIN6 Logic Diagram FSK / DATA / nFFSPIN10 Logic Diagram nRES I/O Note These pins can be left floatingPin Function vs. Operation Mode Si4421Typical Application Recommended supply decoupling capacitor valuesSi4421 GENERAL DEVICE SPECIFICATIONS Absolute Maximum Ratings non-operatingRecommended Operating Range ELECTRICAL SPECIFICATION DC CharacteristicsSi4421 AC Characteristics PLL parameters AC Characteristics ReceiverSi4421 AC Characteristics Others Si4421AC Characteristics Transmitter AC Characteristics Turn-on/TurnaroundtimingsNote 10 By design Si4421Si4421 CONTROL INTERFACE Timing SpecificationTiming Diagram Control Commands Control Register Default ValuesSi4421 Si4421 Description of the Control CommandsConfiguration Setting Command 2. Power Management CommandSi4421 Logic connections between power control bitsSi4421 Frequency Setting Command4. Data Rate Command 5. Receiver Control CommandSi4421 VDI Logic DiagramSi4421 6. Data Filter CommandSi4421 7.FIFO and Reset Mode CommandSi4421 8. Synchron Pattern Command9. Receiver FIFO Read Command 10. AFC CommandBit 5-4rl1 to rl0 Si442111. TX Configuration Control Command Frequency Setting CommandSi4421 13. Transmitter Register Write Command 12. PLL Setting CommandSi4421 14. Wake-UpTimer Command 15.Low Duty-CycleCommandSi4421 Si4421 Vlb= 2.25 + V · 0.1 V Clock divider configuration17. Status Read Command Si4421Bit Name Si4421 INTERRUPT HANDLING Si4421 TX REGISTER BUFFERED DATA TRANSMISSIONTypical TX register usage Si4421RECOMMENDED PACKET STRUCTURES Si4421 RX FIFO BUFFERED DATA READBit Rate 38.4 kbps Si4421 CRYSTAL SELECTION GUIDELINESBit Rate 2.4 kbps Bit Rate 9.6 kbpsSi4421 RX-TXALIGNMENT PROCEDURES Si4421 RESET MODES Si4421 Sensitive Reset Enabled, Ripple on VddFIFO and Reset Mode Command page SW Reset CommandChannel Selectivity and Blocking Si4421 TYPICAL PERFORMANCE CHARACTERISTICSSi4421 BER Curves in 433 MHz BandBER Curves in 868 MHz Band 434 MHz Si4421Frequency Dependent Component Values Si4421 REFERENCE DESIGNSSchematics Evaluation Board with 50 Ohm Matching NetworkPCB Layout Top View Bottom View Si4421Frequency Dependent Component Values SchematicsSi4421 Evaluation Board with Resonant PCB Antenna BIFASi4421 PCB Layout Antenna designed for 868/915 MHz bandTop View Bottom View Si4421 PACKAGE INFORMATION 16-pinTSSOPSee Detail “A” Section B-B Related Resources RELATED PRODUCTS AND DOCUMENTSSi4421 Universal ISM Band FSK Transceiver Demo Boards and Development KitsSi4421