Manuals / Silicon Laboratories / Computer Equipment / Clock

Silicon Laboratories SI5366, SI5369, SI5365 Output Driver Configuration, Typical Output Circuits

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

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Si53xx-RM

8.2. Output Clock Drivers

The output clocks can be configured to be compatible with LVPECL, CML, LVDS, or CMOS as shown in Table 56.

Unused outputs can be left unconnected. For microprocessor-controlled devices, it is recommended to write “disable” to SFOUTn to disable the output buffer and reduce power. When the output mode is CMOS, bypass mode is not supported.

Table 56. Output Driver Configuration

Output Mode	SFOUTn Pin Settings	SFOUTn_REG [2:0] Settings
	(Si5316, Si5322, Si5323, Si5365)	(Si5319, Si5325, SI5326, Si5327,
		Si5367, Si5368, Si5369, Si5374,
		Si5375)

LVDS	HM	111

CML	HL	110

LVPECL	MH	101

Low-swing	ML	011
LVDS

CMOS	LH	010

Disabled	LM	000

Reserved	All Others	All Others

Note: The LVPECL outputs are “LVPECL compatible.” No DC biasing circuitry is required to drive a standard LVPECL load.

8.2.1. LVPECL TQFP Output Signal Format Restrictions at 3.3 V (Si5367, Si5368, Si5369)

The LVPECL and CMOS output formats draw more current than either LVDS or CML; however, there are restrictions in the allowed output format pin settings so that the maximum power dissipation for the TQFP devices is limited when they are operated at 3.3 V. When Vdd = 3.3 V and there are four enabled LVPECL or CMOS outputs, the fifth output must be disabled. When Vdd = 3.3 V and there are five enabled outputs, there can be no more than three outputs that are either LVPECL or CMOS. All other configurations are valid, including those with Vdd = 2.5 V.

8.2.2. Typical Output Circuits

It is recommended that the outputs be ac coupled to avoid common mode issues. This suggestion does not apply to the Si5366 and Si5368 when CKOUT5 is configured as FS_OUT (frame sync) because it can a have a duty cycle significantly different from 50%.

Si53xx

Z0 = 50 Ω

100 Ω

Z0 = 50 Ω

Rcvr

Figure 42. Typical Output Circuit (Differential)

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Silicon Laboratories SI5366, SI5369, SI5365, SI5367, SI5374, SI5375 manual Output Driver Configuration, Typical Output Circuits

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 Precision Clock Multipliers Wideband Product Selection Guide Si5322/25/65/67Device 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 Min Typ Max Unit Device SpecificationsParameter Symbol Test Condition Recommended Operating Conditions1 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 Jitter Transfer PLL PerformanceJitter Generation Jitter Tolerance Jitter Tolerance Mask/Template Clock Multiplication Si5316, Si5322, Si5323, Si5365, Si5366 Si5316, Si5322, Si5323, Si5365 and Si5366 Key FeaturesFrequency Settings Pin Control Parts Si5316, Si5322, Si5323, Si5365, Si5366 FRQSEL10 Nominal Frequency Values MHz BW10 Input Divider SettingsSi5316 Bandwidth Values CKnDIV N3n Input Divider Ckconf = Sonet Clock Multiplication Settings FRQTBL=LClock Multiplication Si5322, Si5323, Si5365, Si5366 Fsout MHz All Devices Si5366 Only FOUT MHz FIN MHz Mult Factor Mllm Hlll Hhlh MHz Mult Factor OUT* MHz Datacom Clock Multiplication Settings Frqtbl = M, Ckconf =Setting 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 Input-to-Output Skew Si5322 and Si5365 Clock Output Divider Control DIV34CKOUT3 and CKOUT4 Si5365 and Si5366 Lock Detect 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 Automatic/Manual Clock Selection Clock Active Indicators Autosel = M or H Si5322 and Si5323Clock Active Indicators Autosel = M or H Si5365 and Si5367 Input Clock Priority for Auto Switching Si5322, Si5323 Hitless Switching with Phase Build-Out Si5323, Si5366 Input Clock Priority for Auto Switching Si5365, Si5366 Narrowband Digital Hold Si5316, Si5323, Si5366 Recovery from Digital Hold Si5316, Si5323, Si5366Digital Hold/VCO Freeze Frame Synchronization Si5366 Including Fsync Inputs in Clock Selection Si5366 Output Phase Adjust Si5323, Si5366Using Fsout as a Fifth Output Clock Si5366 Fsync Realignment Si5366 Output Clock Drivers Fsout Disable Control DblfsOutput Signal Format Selection Sfout DSBL2/BYPASS Pin Settings PLL Bypass ModeAlarms Frequency Offset Control Fosctl Alarm Output Logic Equations Lock Detect Retrigger Time Device ResetDSPLLsim Configuration Software Wideband PLL Divider Settings Si5325, Si5367 Input to Output Skew Si5325, Si5367 Loop Bandwidth Si5325, Si5367Lock Detect Si5325, Si5367 Dividers and Limits Signal Frequency Limits Initiating Internal Self-Calibration Loop Bandwidth Si5319, Si5326, Si5368, Si5375Low Loop Bandwidth Si5324, Si5327, Si5369, Si5374 Ckoutalwayson and Sqical Truth Table Input Clock Control Input Clock Configurations Si5367 and Si5368 CKIN1,2,3,4 inputs CKIN1,3 & CKIN2,4 clock/FSYNC pairs Manual Input Clock Selection Si5367, Si5368, Si5369Active Input Clock Register Bits 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 Fine Skew Control Si5326, Si5368 Output Phase Adjust Si5326, Si5368Unlimited Coarse Skew Adjustment Si5326, Si5368 Coarse Skew Control Si5326, Si5368 Input-to-Output Skew All Devices Frame Synchronization Realignment Si5368 and Ckconfigreg =Output Phase Adjust Si5324, Si5327, Si5369, Si5374 Independent Skew Si5324, Si5326, Si5368, Si5369, Si5374 CKINn Frequency kHz Divisor CKIN3/CKIN4 Frequency Selection Ckconf = Alarm Trigger Threshold Units of T CKOUT2 Common NC5 Divider SettingsAlignment Alarm Trigger Threshold CKOUT2 Frequency MHz NC5 Divider Setting KHz Fsout Fsout Polarity and Pulse Width Control Si5368 Using Fsout as a Fifth Output Clock Si5368Fsync Skew Control Si5368 Including Fsync Inputs in Clock Selection Si5368 Disabling CKOUTn Output Signal Format Selection LOS Selection Loss-of-Signal Validation TimesLoss-of-Signal Registers Clock Validation Time FOS Algorithm Si5324, Si5325, Si5326, Si5368, Si5369, Si5374 Si5326 Si5368 FOS Reference Clock SelectionCLKnRATE Registers FOS Reference 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 InstructionBYTE0 Address/Data70BYTE1 SPI Command FormatSerial Microprocessor Interface SPI 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 Name Sfout Pin Sfout Code Single Diff Vocm Vpk-pk Output Format Measurements1,2Typical Clock Output Scope Shots 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 RATE10 Resonator/External Clock SelectionApproved Crystals XA/XB Reference Sources and Frequencies 38.88MHz XO, 38.88MHz CKIN, 38.88MHz Ckout Fundamental Mode Crystals Reference DriftReference Jitter High f3 Value Phase Noise versus f3, 155.52 MHz in, 622.08 MHz outPhase DBc/Hz Noise Offset Frequency Hz MHz Out Jitter Bandwidth Yellow, fs RMS Blue, fs RMS Reference vs. Output FrequencyMHz in, 622.08 MHz out, 696.399 MHz out Yellow-696.399 MHz output Blue-622.08 MHz output MHz thru 163 MHz Ext Ref, 155.52 MHz in, 622.08 MHz out High Reference Frequency SONETOC192C, 50 kHz to 80 MHz MHz thru 180 MHz Ext Ref, 155.52 MHz in, 622.08 MHz outSONETOC192A, 20 kHz to 80 MHz SONETOC192B, 4 MHz 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 Jitter Values for Figure MHz in, 173.371 MHz and 693.493 MHz outDBc/Hz Offset Frequency Hz 685 MHz In 173.371 MHz Out 685 MHz In 693.493 MHz Out Jitter Bandwidth MHz Input Jitter RMS MHz and 156.25MHz in, 622.08 MHz outDBc/Hz MHz In 1 GHz Out Jitter Band Digital Video HD-SDIMHz in, 148.5 MHz out Appendix D-ALARM Structure Si5368 Alarm Diagram 1 Si5368 Alarm Diagram 2 Pin # Si5322 Pull? Si5316 Pullup/DownSi5322 Pullup/Down Pin # Si5316 Pull? Pin # Si5326 Pull? Si5323 Pullup/DownSi5319, Si5324, Pullup/Down Pin # Si5323 Pull? Pin # Si5325 Pull? Si5325 Pullup/DownSi5326 Pullup/Down Pin # Si5365 Pull? Si5327 Pullup/DownSi5365 Pullup/Down Pin # Si5327 Pull? Pin # Si5366 Pull? Si5366 Pullup/Down Pin # Si5368 Pull? Si5367 Pullup/DownSi5368 Pullup/Down Pin # Si5367 Pull? Pin # Si5374/75 Pull? Si5369 Pullup/DownSi5374/75 Pullup/Down MHz in, 622.08 MHz out Bypass 622.08 MHz In, 622.08 MHz Out MHz in, 155.52 MHz out Bandwidth = 110 Hz Power Supply Noise RejectionPower Supply Noise to Output Transfer Function Hz loop KHz loop Clock Input Crosstalk Results Test ConditionsJitter Band MHz MHz out 622.084 MHz Out No crosstalk 155.52 MHz 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 Hz in, 622.08 M Hz out Jitter vs. Output Format 19.44 MHz In, 622.08 MHz OutSpectrum Analyzer Agilent Model E444OA Output Format vs. Jitter Jitter, fs Test ConditionsInput Frequency Variation = ±50 ppm MHz External XA-XB Reference 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 Jitter, fsec RMS Si5374, Si5375 Crosstalk Test BedSi5374/75 Crosstalk Jitter Values Si5374, Si5375 Dspll a Si5374, Si5375 Dspll B Si5374, Si5375 Dspll C Si5374, Si5375 Dspll D Revision 0.42 to Revision Revision 0.3 to RevisionRevision 0.4 to Revision Revision 0.41 to Revision Rev 179 Contact Information