1
Precision Edge®
SY89831U
Micrel, Inc.
M9999-072210
hbwhelp@micrel.com or (408) 955-1690
DESCRIPTION
■ Guaranteed AC performance over temperature
and voltage:
• DC-to>2.0GHzthroughput
• <450pspropagationdelay(IN-to-Q)
• <20pswithin-deviceskew
• <225psrise/falltime
■ Ultra-lowjitterdesign:
• <62fsRMSphasejitter(Typ)
■ Uniquepatent-pendinginputterminationandVTpin
acceptsDC-andAC-coupleddifferentialinputs
■ 800mV,100KLVPECLoutputswing
■ Powersupply2.5V±5%or3.3V±10%
■ Industrialtemperaturerange: –40°Cto+85°C
■ Availablein16-pin(3mmx3mm)MLF®package
FEATURES
ULTRA-PRECISION 1:4LVPECL
FANOUTBUFFER/TRANSLATOR
WITHINTERNALTERMINATION
Precision Edge®
SY89831U
APPLICATIONS
■ Processorclockdistribution
■ SONETclockdistribution
■ FibreChannelclockdistribution
■ GigabitEthernetclockdistribution
1
The SY89831U is a high-speed, 2GHz differential LVPECL
1:4 fanout buffer optimized for ultra-low skew applications.
Within device skew is guaranteed to be less than 20ps (5ps
typ.) over supply voltage and temperature. The differential
input buffer has a unique internal termination design that
allows access to the termination network through a VT pin.
This feature allows the device to easily interface to different
logic standards. A VREF–AC reference output is included for
AC-coupled applications.
The SY89831U is a part of Micrel's high-speed clock
synchronization family. For applications that require a
different I/O combination, consult Micrel’s website at: www.
micrel.com, and choose from a comprehensive product line
of high-speed, low-skew fanout buffers, translators and clock
generators.
FUNCTIONALBLOCKDIAGRAM TYPICALPERFORMANCE
Precision Edge is a registered trademark of Micrel, Inc.
MicroLeadFrame and MLF are registered trademarks of Amkor Technology, Inc.
Precision Edge®
Rev.: F Amendment: /0
Issue Date: July 2010
2
Precision Edge®
SY89831U
Micrel, Inc.
M9999-072210
hbwhelp@micrel.com or (408) 955-1690
PACKAGE/ORDERINGINFORMATION
Ordering Information(1)
Package Operating Package Lead
PartNumber Type Range Marking Finish
SY89831UMI MLF-16 Industrial 831U Sn-Pb
SY89831UMITR(2) MLF-16 Industrial 831U Sn-Pb
SY89831UMG(3) MLF-16 Industrial 831U with Pb-Free NiPdAu
bar-line indicator Pb-Free
SY89831UMGTR(2, 3) MLF-16 Industrial 831U with Pb-Free NiPdAu
bar-line indicator Pb-Free
Notes:
1. Contact factory for die availability. Dice are guaranteed at TA = 25°C, DC Electricals
only.
2. Tape and Reel.
3. Pb-Free package is recommended for new designs.
PinNumber PinName PinFunction
15, 16 Q0, /Q0 Differential 100K LVPECL Outputs: These LVPECL outputs are the precision, low skew copies
1, 2, Q1, /Q1 of the inputs. Please refer to the “Truth Table” section for details. Unused output pairs may be
3, 4, Q2, /Q2 left open. Terminate wtih 50ý to VCC–2V. See “Output Termination Recommendations” section
5, 6 Q3, /Q3 for more details.
8 EN This single-ended TTL/CMOS-compatible input functions as a synchronous output enable. The
synchronous enable ensures that enable/disable will only occur when the outputs are in a logic
LOW state. Note that this input is internally connected to a 25ký pull-up resistor and will default
to logic HIGH state (enabled) if left open.
9, 12 /IN, IN Differential Inputs: These input pairs are the differential signal inputs to the device. Inputs
accept AC- or DC-Coupled differential signs as small as 100mV. Each pin of a pair internally
terminates to a VT pin through 50ý. Note that these inputs will default to an intermediate state if
left open. Pleae refer to the “Input Interface Applications” section for more details.
10 VREF–AC Reference Voltage: These outputs bias to VCC–1.4V. They are used when AC coupling the
inputs (IN, /IN). For AC-Coupled applications, connect VREF-AC to VT pin and bypass with
0.01µF low ESR capacitor to VCC. See “Input Interface Applications” section for more details.
Maximum sink/source current is ±1.5mA. Due to the limited drive capability, each VREF-AC pin
is only intended to drive its respective VT pin. If VREF-AC is used with a 2.5V supply, make
sure input swing is large enough to not violate VIH min. spec.
11 VT Input Termination Center-Tap: Each side of the differential input pair terminates to a VT pin. The
VTpinsprovideacenter-taptoaterminationnetworkformaximuminterfaceexibility.See“Input
Interface Applications” section for more detaiils.
13 GND Ground. GND pins and exposed pad must be connected to the most negative potential of the
device ground.
7, 14 VCC Positive Power Supply: Bypass with 0.1µF//0.01µF low ESR capacitors and place as close to
each VCC pin as possible.
PIN DESCRIPTION
16-PinMLF®(MLF-16)
IN /IN EN Q /Q
0 1 1 0 1
1 0 1 1 0
X X 0 0(1) 1
(1)
Note:
1. On next negative transition of the input signal (IN).
TRUTHTABLE
3
Precision Edge®
SY89831U
Micrel, Inc.
M9999-072210
hbwhelp@micrel.com or (408) 955-1690
AbsoluteMaximumRatings(1)
Supply Voltage (VCC) ....................................–0.5V to +4.0V
Input Voltage (VIN) .................................–0.5V to VCC
+0.5V
LVPECL Output Current (IOUT)
Continuous .......................................................... 50mA
Surge ................................................................ 100mA
Input Current
Source or Sink Current on (IN, /IN) ................... ±50mA
VREF-AC Current
Source or Sink Current on (IVT) .......................... ±2mA
Lead Temperature (soldering, 20sec.) ....................... 260°C
Storage Temperature (TS) ........................ –65°C to +150°C
Operating Ratings(2)
Supply Voltage Range ......................... +2.375V to +2.625V
............................................................. +3.0V to +3.6V
Ambient Temperature (TA) .......................... –40°C to +85°C
Package Thermal Resistance(3)
MLF™
(θJA) Still-Air ...................................................................... 60°C/W
(ΨJB) Junction-to-Board ......................................32°C/W
TA = –40°C to +85°C, unless otherwise stated.
Symbol Parameter Condition Min Typ Max Units
VCC Power Supply 2.375 2.625 V
3.0 3.6
ICC Power Supply Current No load, max. VCC. 47 70 mA
RIN Input Resistance (IN-to-VT) 45 50 55 ý
RDIFF-IN Differential Input Resistance
(IN-to-/IN) 90 100 110 ý
VIH Input HIGH Voltage (IN, /IN) 1.2 VCC V
VIL Input LOW Voltage (IN, /IN) 0 VIH–0.1 V
VIN Input Voltage Swing (IN, /IN) see Figure 1a. 0.1 1.7 V
VDIFF_IN Differential Input Voltage Swing
|IN – /IN| see Figure 1b. 0.2 V
VREF–AC Output Reference Voltage
V
CC–1.525 VCC–1.425 VCC–1.325 V
DCELECTRICALCHARACTERISTICS(4)
VCC = 2.375V to 3.60V; VEE = 0V; TA = –40°C to +85°C
Symbol Parameter Condition Min Typ Max Units
VIH Input HIGH Voltage 2.0 VCC V
VIL Input LOW Voltage 0 0.8 V
IIH Input HIGH Current –125 20 µA
IIL Input LOW Current –300 µA
Notes:
1. Permanent device damage may occur if absolute maximum ratings are exceeded. This is a stress rating only and functional operation is not implied
at conditions other than those detailed in the operational sections of this data sheet. Exposure to absolute maximum ratlng conditions for extended
periods may affect device reliability.
2. The data sheet limits are not guaranteed if the device is operated beyond the operating ratings.
3. Packagethermalresistanceassumesexposedpadissoldered(orequivalent)tothedevice’smostnegativepotentialonthePCB.ψJBandθJA values
are determined for a 4-layer board in stil-air number, unless otherrwise stated.
4. ThecircuitisdesignedtomeettheDCspecicationsshownintheabovetableafterthermalequilibriumhasbeenestablished.
LVTTL/LVCMOSINPUTDCELECTRICALCHARACTERISTICS
4
Precision Edge®
SY89831U
Micrel, Inc.
M9999-072210
hbwhelp@micrel.com or (408) 955-1690
VCC = +2.5V ±5% or +3.3V ±10%; RL = 50ý to VCC –2V; TA = –40°C to +85°C unless otherwise stated.
Symbol Parameter Condition Min Typ Max Units
VOH Output HIGH Voltage
(Q, /Q) VCC–1.145 VCC–0.895 V
VOL Output LOW Voltage
(Q, /Q) VCC–1.945 VCC–1.695 V
VOUT Output Voltage Swing
(Q, /Q) See Figure 1a. 550 800 mV
VDIFF_OUT Differential Output Voltage Swing
(Q, /Q) See Figure 1b. 1100 1600 mV
LVPECLOUTPUTDCELECTRICALCHARACTERISTICS(6)
VCC = +2.5V ±5% or +3.3V ±10%; TA = –40°C to +85°C unless otherwise stated.
Symbol Parameter Condition Min Typ Max Units
VIH Input HIGH Voltage 2.0 VCC V
VIL Input LOW Voltage 0.8 V
IIH Input HIGH Voltage –125 30 µA
IIL Input LOW Voltage –300 µA
Notes:
6. ThecircuitisdesignedtomeettheDCspecicationsshownintheabovetableafterthermalequilibriumhasbeenestablished.
LVTTL/CMOSDCELECTRICALCHARACTERISTICS(6)
5
Precision Edge®
SY89831U
Micrel, Inc.
M9999-072210
hbwhelp@micrel.com or (408) 955-1690
VCC = +2.5V ±5% or +3.3V ±10%; RL = 50ý to VCC –2V; TA = –40°C to +85°C unless otherwise stated.
Symbol Parameter Condition Min Typ Max Units
fMAX Maximum Frequency VOUTž450mV 2.0 2.5 GHz
tpd Propagation Delay IN-to-Q VINž100mV 390 ps
IN-to-Q VINž 800mV 250 350 450 ps
tSKEW Within-Device Skew Note 8 5 20 ps
Part-to-Part Skew Note 9 150 ps
tS Set-Up Time EN to IN, /IN Note10 300 ps
tH Hold Time EN to IN, /IN Note10 300 ps
tJITTER RMS Phase Jitter Output = 622MHz 62 fs
Integration Range 12kHz - 20MHz
tr, tf Output Rise/Fall Times At full output swing. 70 150 225 ps
(20% to 80%)
Notes:
7. High-frequency AC parameters are guaranteed by design and characterization.
8. Within device skew is measured between two different outputs under identical input transitions.
9. Part-to-partskewisdenedfortwopartswithidenticalpowersupplyvoltagesatthesametemperatureandnoskewattheedgesattherespective
inputs.
10. Set-up and hold times apply to synchronous applications that intend to enable/disable before the next clock cycle. For asynchronous applications,
set-up and hold times do not apply.
ACELECTRICALCHARACTERISTICS(7)
PHASENOISE
6
Precision Edge®
SY89831U
Micrel, Inc.
M9999-072210
hbwhelp@micrel.com or (408) 955-1690
TYPICALOPERATINGCHARACTERISTICS
0
100
200
300
400
500
600
700
800
900
0 1000 2000 3000
FREQUENCY (MHz)
Output Swing
vs. Frequency
300
310
320
330
340
350
360
370
380
390
-40 -20 0 20 40 60 80 100
TEMPERATURE (°C)
Propagation Delay
vs. Temperature
300
325
350
375
400
425
450
100 300 500 700 900
INPUT VOLTAGE SWING (V)
Propagation Delay
vs. Input Voltage Swing
VCC = 3.3V, GND = 0V, RL = 50ý to VCC–2V, TA = 25°C, unless otherwise stated.
7
Precision Edge®
SY89831U
Micrel, Inc.
M9999-072210
hbwhelp@micrel.com or (408) 955-1690
FUNCTIONALCHARACTERISTICS
VCC = 3.3V, GND = 0V, VIN = 800mV, RL = 50ý to VCC–2V, TA = 25°C, unless otherwise stated.
8
Precision Edge®
SY89831U
Micrel, Inc.
M9999-072210
hbwhelp@micrel.com or (408) 955-1690
INPUT AND OUTPUT STAGES
Figure2a. SimpliedDifferential
Figure1a. Single-EndedSwing Figure1b. DifferentialSwing
SINGLE-ENDEDANDDIFFERENTIALSWINGS
Figure2b. SimpliedLVPECLOutputStage
9
Precision Edge®
SY89831U
Micrel, Inc.
M9999-072210
hbwhelp@micrel.com or (408) 955-1690
INPUTINTERFACEAPPLICATIONS
Figure3c. DC-CoupledCML
Input Interface
Figure3d. AC-CoupledCML
Input Interface
Figure3a. DC-CoupledLVPECL
Input Interface
Figure3b. AC-CoupledLVPECL
Input Interface
For 2.5V, Rpd = 50ý
For 3.3V, Rpd = 100ý
Figure3e. LVDSInterface
10
Precision Edge®
SY89831U
Micrel, Inc.
M9999-072210
hbwhelp@micrel.com or (408) 955-1690
OUTPUT TERMINATION RECOMMENDATIONS
Figure 4. Parallel Termination—
Thevenin Equivalent
Note:
1. For +2.5V systems: R1 = 250ý, R2 = 62.5ý.
PartNumber Function DataSheetLink
SY89830U 1:4 LVPECL Fanout Buffer w/2:1 MUX Input www.micrel.com/product-info/products/sy89830u.shtml
SY89832U 2.5V Ultra-Precision 1:4 LVDS Fanout Buffer/ www.micrel.com/product-info/products/sy89832u.shtml
Translator with Internal Termination
SY89833U 3.3V Ultra-Precision 1:4 LVDS Fanout Buffer/ www.micrel.com/product-info/products/sy89833u.shtml
Translator with Internal Termination
SY89834U 2.5/3.3V Two Input, 1GHz LVTTL/CMOS-to-LVPECL www.micrel.com/product-info/products/sy89833u.shtml
1:4 Fanout Buffer/Translator
HBW Solutions New Products and Applications www.micrel.com/product-info/products/solutions.shtml
16-MLF® Manufacturing Guidelines
www.amkor.com/products/notes_papers/MLF_AppNote_0301.pdf
Exposed Pad Application Note
RELATEDPRODUCTANDSUPPORTDOCUMENTATION
Figure 5. Three-Resistor “Y-Termination”
Notes:
1. Power-saving alternative to Thevenin termination.
2. Place termination resistors as close to destination inputs as possible.
3. Rb resistor sets the DC bias voltage, equal to Vt.
For +2.5V systems Rb = 19ý.
4. C1 is an optional bypass capacitor intended to compensate for any tr/tf
mismatches.
11
Precision Edge®
SY89831U
Micrel, Inc.
M9999-072210
hbwhelp@micrel.com or (408) 955-1690
PCBThermalConsiderationfor16-PinMLF® Package
(Alwayssolder,orequivalent,theexposedpadtothePCB)
16-PINEPAD MicroLeadFrame®(MLF-16)
PackageNotes:
Note 1. PackagemeetsLevel2moisturesensitivityclassication,andareshippedindry-packform.
Note2. Exposed pads must be soldered to a ground for proper thermal management.
MICREL,INC. 2180FORTUNEDRIVE SANJOSE,CA 95131 USA
t e l + 1 (408) 944-0800 f a x + 1 (408) 474-1000 w e b http://www.micrel.com
The information furnished by Micrel in this datasheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use.
Micrelreservestherighttochangecircuitryandspecicationsatanytimewithoutnoticationtothecustomer.
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thebodyor(b)supportorsustainlife,andwhosefailuretoperformcanbereasonablyexpectedtoresultinasignicantinjurytotheuser.APurchaser’s
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