Manuals / Silicon Laboratories / Computer Equipment / Clock

Silicon Laboratories SI5326 Input Clock Configurations Si5367 and Si5368, Input Clock Control

Models: SI5326 SI5319 SI5369 SI5324 SI5367 SI5322 SI5316 SI5327 SI5366 SI5374 SI5325 SI5323 SI5368 SI5365 SI5375

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Si53xx-RM

7.3. Input Clock Configurations (Si5367 and Si5368)

The device supports two input clock configurations based on CK_CONFIG_REG. See "6.5. Frame Synchronization (Si5366)" on page 70 for additional details.

7.4. Input Clock Control

This section describes the clock selection capabilities (manual input selection, automatic input selection, hitless switching, and revertive switching). The Si5319, Si5327, and Si5375 support only pin-controlled manual clock selection. Figure 27 and Figure 28 provide top level overviews of the clock selection logic, though they do not cover wideband or frame sync applications. Register values are indicated by underscored italics. Note that, when switching between two clocks, LOL may temporarily go high if the clocks differ in frequency by more than 100 ppm.

CKIN1

CKIN2

CK_PRIORn 4

Selected

Clock

	LOS/FOS			LOS/FOS
	detect			detect

Clock priority logic

CKSEL_REG

1

0

CS_CA pin

AUTOSEL_REG

CKSEL_PIN

2

decode

Auto

Manual

0

1

CK_ACTV_PIN

Figure 27. Si5324, Si5325, Si5326, Si5327, and Si5374 Input Clock Selection

Rev. 0.5

81

Image 81

Silicon Laboratories SI5326, SI5369, SI5365, SI5366, SI5367 Input Clock Configurations Si5367 and Si5368, Input Clock Control

Contents

ANY-FREQUENCY Precision Clocks Si53xx-RM Table of Contents Output Clock Drivers High-Speed I/O Si5375 Free Run Mode Si53xx-RM List of Figures Differential Output Example Requiring Attenuation 108 Si53xx-RM List of Tables Si53xx-RM Any-Frequency Precision Clock Product Family Overview Si53xx-RM PLL Product Selection Guide Product Selection Guide Si5322/25/65/67 DevicePrecision Clock Multipliers Wideband Narrowband vs. Wideband Overview Si5316 Any-Frequency Clock Family Members Dspll Si5319 Si5322 Si5322 Low Jitter Clock Multiplier Block Diagram Si5323 Si5323 Jitter Attenuating Clock Multiplier Block Diagram Si5324 Si5324 Clock Multiplier and Jitter Attenuator Block Diagram Si5325 Si5325 Low Jitter Clock Multiplier Block Diagram Si5326 Si5326 Clock Multiplier and Jitter Attenuator Block Diagram Si5327 Si5327 Clock Multiplier and Jitter Attenuator Block Diagram Si5365 Si5365 Low Jitter Clock Multiplier Block Diagram 10. Si5366 Si5366 Jitter Attenuating Clock Multiplier Block Diagram 11. Si5367 Si5367 Clock Multiplier Block Diagram 12. Si5368 Si5368 Clock Multiplier and Jitter Attenuator Block Diagram 14. Si5374/75 Compared to Si5324/19 13. Si5369 15. Si5374 Si5374 Functional Block Diagram 16. Si5375 Si5375 Functional Block Diagram Parameter Symbol Test Condition Device SpecificationsRecommended Operating Conditions1 Min Typ Max Unit CKINn Input Pins DC Characteristics Lvpecl 100 Ω Level Input Pins Level Lvcmos Input Pins RST Lvcmos Output Pins Parameter Symbol Test Conditions Min Typ Max Unit SPI Specifications Si5324, Si5325, Si5367, and Si5368 SDO Differential Reference Clock Input Pins XA/XB Frame Synchronization Timing Min Typ Max Units AC Characteristics-All Devices Lvcmos Pins PLL Performance Device Skew Ckopn Jitter Generation Si5322, Si5325, Si5365, Si5367 Jitter Generation Si5316, Si5324, Si5366, Si5368 Parameter Symbol Test Condition Devices Value Unit Thermal Characteristics Dspll All Devices Any-Frequency Precision Clock Dspll Block Diagram Clock Multiplication Circuit Clock Multiplication PLL Performance Jitter GenerationJitter Transfer Jitter Tolerance Jitter Tolerance Mask/Template Frequency Settings Si5316, Si5322, Si5323, Si5365 and Si5366 Key FeaturesPin Control Parts Si5316, Si5322, Si5323, Si5365, Si5366 Clock Multiplication Si5316, Si5322, Si5323, Si5365, Si5366 Si5316 Bandwidth Values Input Divider SettingsCKnDIV N3n Input Divider FRQSEL10 Nominal Frequency Values MHz BW10 Clock Multiplication Si5322, Si5323, Si5365, Si5366 Sonet Clock Multiplication Settings FRQTBL=LFsout MHz Ckconf = All Devices Si5366 Only FOUT MHz FIN MHz Mult Factor Mllm Hlll Hhlh Datacom Clock Multiplication Settings Frqtbl = M, Ckconf = SettingMHz Mult Factor OUT* MHz 125 10/8 x 66/64 161.13 173.37 X 64/66 x 237/255 125 Hhhl FIN MHz Mult Factor FOUT* MHz Sonet to Datacom Clock Multiplication Settings 62.500 125 155.520 15625/15552 156.25 CKOUT3 and CKOUT4 Si5365 and Si5366 Clock Output Divider Control DIV34Lock Detect Si5322 and Si5365 Input-to-Output Skew Si5322 and Si5365 PLL Self-Calibration Si5365 and Si5366 Pins and Reset Si5316, Si5322, and Si5323 Pins and Reset Manual Input Clock Selection Si5365, Si5366, Autosel = L Pin Control Input Clock Control Clock Active Indicators Autosel = M or H Si5365 and Si5367 Clock Active Indicators Autosel = M or H Si5322 and Si5323Input Clock Priority for Auto Switching Si5322, Si5323 Automatic/Manual Clock Selection Hitless Switching with Phase Build-Out Si5323, Si5366 Input Clock Priority for Auto Switching Si5365, Si5366 Digital Hold/VCO Freeze Recovery from Digital Hold Si5316, Si5323, Si5366Frame Synchronization Si5366 Narrowband Digital Hold Si5316, Si5323, Si5366 Using Fsout as a Fifth Output Clock Si5366 Output Phase Adjust Si5323, Si5366Fsync Realignment Si5366 Including Fsync Inputs in Clock Selection Si5366 Fsout Disable Control Dblfs Output Signal Format Selection SfoutOutput Clock Drivers PLL Bypass Mode AlarmsDSBL2/BYPASS Pin Settings Frequency Offset Control Fosctl Alarm Output Logic Equations Device Reset DSPLLsim Configuration SoftwareLock Detect Retrigger Time Wideband PLL Divider Settings Si5325, Si5367 Loop Bandwidth Si5325, Si5367 Lock Detect Si5325, Si5367Input to Output Skew Si5325, Si5367 Dividers and Limits Signal Frequency Limits Loop Bandwidth Si5319, Si5326, Si5368, Si5375 Low Loop Bandwidth Si5324, Si5327, Si5369, Si5374Initiating Internal Self-Calibration Ckoutalwayson and Sqical Truth Table Input Clock Control Input Clock Configurations Si5367 and Si5368 Active Input Clock Manual Input Clock Selection Si5367, Si5368, Si5369Register Bits CKIN1,2,3,4 inputs CKIN1,3 & CKIN2,4 clock/FSYNC pairs Ckselreg or CS pin Active Input Clock Manual Input Clock Selection Si5324, Si5325, Si5326, Si5374 Selected Clock Input Clock Priority for Auto Switching Clock Control Logic in Free Run Mode Free Run Mode Programming Procedure  While in Free Run Free Run Reference Frequency Constraints Parameters in History Value of M Digital Hold Digital Hold History Averaging Time Digital Hold History Delay Digital Hold versus VCO Freeze VCO Freeze Si5319, Si5325, Si5367, Si5375 Unlimited Coarse Skew Adjustment Si5326, Si5368 Output Phase Adjust Si5326, Si5368Coarse Skew Control Si5326, Si5368 Fine Skew Control Si5326, Si5368 Output Phase Adjust Si5324, Si5327, Si5369, Si5374 Frame Synchronization Realignment Si5368 and Ckconfigreg =Independent Skew Si5324, Si5326, Si5368, Si5369, Si5374 Input-to-Output Skew All Devices CKINn Frequency kHz Divisor CKIN3/CKIN4 Frequency Selection Ckconf = Alignment Alarm Trigger Threshold Common NC5 Divider SettingsCKOUT2 Frequency MHz NC5 Divider Setting KHz Fsout Alarm Trigger Threshold Units of T CKOUT2 Fsync Skew Control Si5368 Using Fsout as a Fifth Output Clock Si5368Including Fsync Inputs in Clock Selection Si5368 Fsout Polarity and Pulse Width Control Si5368 Disabling CKOUTn Output Signal Format Selection Loss-of-Signal Registers Loss-of-Signal Validation TimesClock Validation Time LOS Selection FOS Algorithm Si5324, Si5325, Si5326, Si5368, Si5369, Si5374 CLKnRATE Registers FOS Reference Clock SelectionFOS Reference Si5326 Si5368 Fosen LOS Si5319, Si5375 11.6. C1B, C2B, C3B, Alrmout Si5368 Ckconfigreg = Alarm Output Logic Equations Si5368 and Ckconfigreg = Device Interrupts Lock Detect Retrigger Time Lockt 13. I2C Serial Microprocessor Interface I2C Command Format SPI Command Format Serial Microprocessor Interface SPIInstructionBYTE0 Address/Data70BYTE1 Register Descriptions Default Device Configuration Input Clock Buffers High-Speed I/O CML/LVDS Termination 1.8, 2.5, 3.3 Typical Output Circuits Output Driver Configuration Output Driver Si5365, Si5366 Si5325, Si5326, Si5367, Si5368 Disabling Unused Output Driver Output Format Measurements1,2 Typical Clock Output Scope ShotsName Sfout Pin Sfout Code Single Diff Vocm Vpk-pk Sfout3, lowSwingLVDS Sfout2, Cmos Sfout5, Lvpecl Sfout7, Lvds Cmos External Reference Circuit OSC-P Parameter Symbol Min Max Three-Level 3L Input Pins No External Resistors Three-Level 3L Input Pins With External Resistors Typical Power Supply Bypass Network Tqfp Package Power Supply Packages and Ordering Guide Approved Crystals Resonator/External Clock SelectionXA/XB Reference Sources and Frequencies RATE10 Fundamental Mode Crystals Reference Drift Reference Jitter38.88MHz XO, 38.88MHz CKIN, 38.88MHz Ckout Phase Noise versus f3, 155.52 MHz in, 622.08 MHz out PhaseHigh f3 Value DBc/Hz Noise Offset Frequency Hz MHz in, 622.08 MHz out, 696.399 MHz out Reference vs. Output FrequencyYellow-696.399 MHz output Blue-622.08 MHz output MHz Out Jitter Bandwidth Yellow, fs RMS Blue, fs RMS MHz thru 163 MHz Ext Ref, 155.52 MHz in, 622.08 MHz out High Reference Frequency SONETOC192A, 20 kHz to 80 MHz MHz thru 180 MHz Ext Ref, 155.52 MHz in, 622.08 MHz outSONETOC192B, 4 MHz to 80 MHz SONETOC192C, 50 kHz to 80 MHz Appendix C-TYPICAL Phase Noise Plots 52 MHz In 622.08 MHz Out Loop BW = 7 Hz, Si5324 44 MHz In 156.25 MHz Out Loop BW = 80 Hz 44 MHz In 156.25 MHz Out Loop BW = 5 Hz, Si5324 130 44 MHz In 491.52 MHz Out Loop BW = 7 Hz, Si5324 08 MHz In 672.16 MHz Out Loop BW = 6.9 kHz 08 MHz In 672.16 MHz Out Loop BW = 100 Hz 25 MHz In 155.52 MHz Out Jitter Bandwidth 644.531 MHz Jitter RMS 125 MHz In 644.531 MHz Out Jitter Values for Figure Jitter Bandwidth 690.569 MHz Jitter RMS 125 MHz In 690.569 MHz Out Jitter Values for Figure Jitter Bandwidth 693.493 MHz Jitter RMS 125 MHz In 693.493 MHz Out Jitter Values for Figure DBc/Hz MHz in, 173.371 MHz and 693.493 MHz outOffset Frequency Hz Jitter Values for Figure 685 MHz In 173.371 MHz Out 685 MHz In 693.493 MHz Out MHz and 156.25MHz in, 622.08 MHz out DBc/HzJitter Bandwidth MHz Input Jitter RMS MHz In 1 GHz Out Digital Video HD-SDI MHz in, 148.5 MHz outJitter Band Appendix D-ALARM Structure Si5368 Alarm Diagram 1 Si5368 Alarm Diagram 2 Si5322 Pullup/Down Si5316 Pullup/DownPin # Si5316 Pull? Pin # Si5322 Pull? Si5319, Si5324, Pullup/Down Si5323 Pullup/DownPin # Si5323 Pull? Pin # Si5326 Pull? Si5325 Pullup/Down Si5326 Pullup/DownPin # Si5325 Pull? Si5365 Pullup/Down Si5327 Pullup/DownPin # Si5327 Pull? Pin # Si5365 Pull? Pin # Si5366 Pull? Si5366 Pullup/Down Si5368 Pullup/Down Si5367 Pullup/DownPin # Si5367 Pull? Pin # Si5368 Pull? Si5369 Pullup/Down Si5374/75 Pullup/DownPin # Si5374/75 Pull? MHz in, 622.08 MHz out Bypass 622.08 MHz In, 622.08 MHz Out Power Supply Noise Rejection Power Supply Noise to Output Transfer FunctionMHz in, 155.52 MHz out Bandwidth = 110 Hz Jitter Band MHz MHz out 622.084 MHz Clock Input Crosstalk Results Test ConditionsOut No crosstalk 155.52 MHz Hz loop KHz loop 5 .5 2 1 M H z in , 6 2 2 .0 8 4 M H z o u t Clock Input Crosstalk Phase Noise Plots 155 .521 MHz in, 622 .084 MHz ou t Clock Input Crosstalk Detail View 155 .521 M H z in, 622.084 M H z out Clock Input Crosstalk Wideband Comparison Clock Input Crosstalk Output of Rohde and Schwartz RF Spectrum Analyzer Agilent Model E444OA Jitter vs. Output Format 19.44 MHz In, 622.08 MHz OutOutput Format vs. Jitter Hz in, 622.08 M Hz out Input Frequency Variation = ±50 ppm Test ConditionsMHz External XA-XB Reference Jitter, fs Input Frequency Variation = ±2000 ppm Input Frequency Fmod Fdev Jitter Start RF Gen Si5326 Si5324 Jitter Values RF Generator, Si5326, Si5324 No Jitter For Reference MHz in, 622.08 MHz out RF Generator, Si5326, Si5324 100 Hz Jitter RF Generator, Si5326, Si5324 1 kHz Jitter RF Generator, Si5326, Si5324 10 kHz Jitter Appendix I-Si5374AND Si5375 PCB Layout Recommendations Ground Plane and Reset Output Clock Routing Oscp Oscn Si5374, Si5375 Crosstalk Test Bed Si5374/75 Crosstalk Jitter ValuesJitter, fsec RMS Si5374, Si5375 Dspll a Si5374, Si5375 Dspll B Si5374, Si5375 Dspll C Si5374, Si5375 Dspll D Revision 0.4 to Revision Revision 0.3 to RevisionRevision 0.41 to Revision Revision 0.42 to Revision Rev 179 Contact Information