SY56020R
Low Voltage 1.2V/1.8V/2.5V CML 1:4
Fanout Buffer 6.4Gbps with Equalization
Precision Edge is a registered trademark of Micrel, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
General Description
The SY56020R is a fully-differential, low-voltage
1.2V/1.8V/2.5V CML 1:4 Fanout Buffer with input
equalization. The SY56020R can process clock signals
as fast as 4.5GHz or data patterns up to 6.4Gbps.
The differential input includes Micrel’s unique, 3-pin input
termination architecture that interfaces to CML
differential signals, without any level-shifting or
termination resistor networks in the signal path. The
differential input can also accept AC-coupled LVPECL
and LVDS signals. Input voltages as small as 200mV
(400mVpp) are applied before the 9”, 18” or 27” FR4
transmission line. For AC-coupled input interface
applications, an internal voltage reference is provided to
bias the VT pin. The outputs are CML, with extremely
fast rise/fall times guaranteed to be less than 90ps.
The SY56020R operates from a 2.5V ±5% core supply
and a 1.2V, 1.8V or 2.5V ±5% output supply and is
guaranteed over the full industrial temperature range
(–40°C to +85°C). The SY56020R is part of Micrel’s
high-speed, Precision Edge® product line.
Datasheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Functional Block Diagram
Precision Edge®
Features
• 1.2V/1.8V/2.5V CML 1:4 Fanout Buffer
• Equalizes 9, 18, 27 inches of FR4
• Guaranteed AC performance over temperature and
voltage:
– DC-to > 6.4Gbps Data throughput
– DC-to > 4.5GHz Clock throughput
– <280 ps propagation delay (IN-to-Q)
– <15ps within-device skew
– <90ps rise/fall times
• Ultra-low jitter design
– <1psRMS random jitter
• High-speed CML outputs
• 2.5V ±5% VCC , 1.2/1.8V/2.5V ±5% VCCO power supply
operation
• Industrial temperature range: –40°C to +85°C
• Available in 16-pin (3mm x 3mm) QFN package
Applications
• Data distribution
• SONET clock and data distribution
• Fiber Channel clock and data distribution
• Gigabit Ethernet clock and data distribution
Markets
• Storage
• ATE
• Test and measurement
• Enterprise networking equipment
• High-end servers
• Metro area network equipment
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Ordering Information
Part Number Package Type Operating Range Package Marking Lead Finish
SY56020RMG QFN-16 Industrial R020 with Pb-Free bar-line indicator NiPdAu
Pb-Free
SY56020RMGTR(2) QFN-16 Industrial R020 with Pb-Free bar-line indicator NiPdAu
Pb-Free
Notes:
1. Contact factory for die availability. Dice are guaranteed at TA = 25°C, DC Electricals only.
2. Tape and Reel.
Pin Configur ation
16-Pin QFN
Truth Table
EQ Equalization FR4 6mil Stripline
LOW 9”
FLOAT 18”
HIGH 27”
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Pin Description
Pin Number Pin Name Pin Function
2,3 IN, /IN
Differential Input: Signals as small as 200mV VPK (400mVPP) applied to the input of 9, 18 or 27
inches 6mil FR4 stripline transmission line are then terminated with this differential input. Each input
pin internally terminates with 50Ω to the VT pin.
1 VT
Input Termination Center-Tap: Each side of the differential input pair terminates to VT pin. This pin
provides a center-tap to a termination network for maximum interface flexibility. An internal high
impedance resistor divider biases VT to allow input AC-coupling. For AC-coupling, bypass VT with
0.1µF low-ESR capacitor to VCC. See “Interface Applications” subsection and Figure 2a.
4 EQ Three level input for equalization control. High, float, low.
16 VCC
Positive Power Supply: Bypass with 0.1µF//0.01µF low-ESR capacitors as close to the VCC pins as
possible. Supplies input and core circuitry.
8,13 VCCO
Output Supply: Bypass with 0.1µF//0.01µF low-ESR capacitors as close to the VCCO pins as
possible. Supplies the output buffers.
5 GND,
Exposed pad
Ground: Exposed pad must be connected to a ground plane that is the same potential as the
ground pins.
15,14
12,11
10,9
7,6
Q0, /Q0
Q1, /Q1
Q2, /Q2
Q3, /Q3
CML Differential Output Pairs: Differential buffered copy of the input signal. The output swing is
typically 390mV. See “Interface Applications” subsection for termination information.
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Absolute Maximum Ratings(1)
Supply Voltage (VCC)............................... –0.5V to +3.0V
Supply Voltage (VCCO) ............................. –0.5V to +3.0V
VCC − VCCO ..............................................................<1.8V
VCCO − VCC ..............................................................<0.5V
Input Voltage (VIN)....................................... –0.5V to VCC
CML Output Voltage (VOUT)......................... 0.6V to 3.0V
Current (VT)
Source or Sink on VT pin.............................±100mA
Input Current
Source or Sink Current on (IN, /IN) ...............±50mA
Maximum Operating Junction Temperature.......... 125°C
Lead Temperature (soldering, 20sec.).................. 260°C
Storage Temperature (Ts) ....................–65°C to +150°C
Operating Ratings(2)
Supply Voltage (Vcc) .................................. 2.375V to 2.625V
(Vcco) ................................... 1.14V to 2.625V
Ambient Temperature (TA)............................–40°C to +85°C
Package Thermal Resistance(3)
QFN
Still-Air (θJA)..............................................................75°C/W
Junction-to-Board (ψJB) ............................................33°C/W
DC Electrical Characteristics(4)
TA = –40°C to +85°C, unless otherwise stated.
Symbol Parameter Condition Min. Typ. Max. Units
VCC
Power Supply Voltage Range
VCC
VCCO
VCCO
VCCO
2.375
1.14
1.7
2.375
2.5
1.2
1.8
2.5
2.625
1.26
1.9
2.625
V
ICC Power Supply Current Maximum VCC. 60 85 mA
ICCO Power Supply Current No Load. Maximum VCCO. 64 84 mA
RIN Input Resistance
(IN-to-VT, /IN-to-VT ) 45 50 55 Ω
RDIFF_IN Differential Input Resistance
(IN-to-/IN) 90 100 110 Ω
VIH Input HIGH Voltage (IN, /IN) IN, /IN 1.42 VCC V
VIL Input LOW Voltage (IN, /IN) IN, /IN
1.22V = 1.7-0.475 1.22 VIH–0.2 V
VIN Input Voltage Swing (IN, /IN) See Figure 3a, applied to input of
transmission line. 0.2 1.0 V
VDIFF_IN Differential Input Voltage Swing
(|IN − /IN|)
See Figure 3b, applied to input of
transmission line. 0.4 2.0 V
VT_IN Voltage from Input to VT 1.28 V
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 ratings 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 still-air number, unless otherwise stated.
4. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
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CML Outputs DC Electrical Charact eristics(5)
VCCO = 1.14V to 1.26V RL = 50Ω to VCCO,
VCCO = 1.7V to 1.9V, 2.375V to 2.625V, RL = 50Ω to VCCO or 100Ω across the outputs.
VCC = 2.375V to 2.625V; TA = –40°C to +85°C, unless otherwise stated.
Symbol Parameter Condition Min. Typ. Max. Units
VOH Output HIGH Voltage RL = 50Ω to VCCO VCC − 0.020 VCC − 0.010 VCC V
VOUT Output Voltage Swing See Figure 3a 300 390 475 mV
VDIFF_OU
T Differential Output Voltage Swing See Figure 3b 600 780 950 mV
ROUT Output Source Impedance 45 50 55 Ω
Three Level EQ Input DC Electrical Characteristi cs(5)
VCC = 2.375V to 2.625V; TA = –40°C to +85°C, unless otherwise stated.
Symbol Parameter Condition Min. Typ. Max. Units
VIH Input HIGH Voltage VCC − 0.3 V
CC V
VIL Input LOW Voltage 0 VEE + 0.3 V
IIH Input HIGH Current VIH = VCC 400 µA
IIL Input LOW Current VIL = GND −480 µA
Note:
5. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
AC Electrical Characteristics
VCCO = 1.14V to 1.26V RL = 50Ω to VCCO,
VCCO = 1.7V to 1.9V, 2.375V to 2.625V, RL = 50Ω to VCCO or 100Ω across the outputs,
VCC = 2.375V to 2.625V; TA = –40°C to +85°C, unless otherwise stated.
Symbol Parameter Condition Min. Typ. Max. Units
NRZ Data 6.4 Gbps
fMAX Maximum Frequency VOUT > 200mV Clock 4.5 GHz
tPD Propagation Delay IN-to-Q Note 6, Figure 1 100 180 280 ps
Output-to-Output Skew Note 7 3 15 ps
tSkew Part-to-Part Skew Note 8 100 ps
tJitter Random Jitter Note 9 1 psRMS
tr tf Output Rise/Fall Time
(20% to 80%) At full output swing. 20 50 90 ps
Notes:
6. Propagation delay is measured with no attenuating transmission line connected to the input.
7. Output-to-Output skew is the difference in time between both outputs, receiving data from the same input, for the same temperature, voltage and
transition.
8. Part-to-part skew is defined for two parts with identical power supply voltages at the same temperature and no skew at the edges at the respective
inputs.
9. Random jitter is measured with a K28.7 pattern, measured at ≤ fMAX.
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Interface Applications
For Input Interface Applications see Figures 4a-e and
for CML Output Termination, see Figures 5a-d.
CML Output Termination with VCCO 1.2V
For VCCO of 1.2V, Figure 5a, terminate the output
with 50Ω to 1.2V, DC coupled, not 100Ω differentially
across the outputs.
If AC-coupling is used, Figure 5d, terminate into 50Ω
to 1.2V before the coupling capacitor and then
connect to a high value resistor to a reference
voltage.
Do not AC-couple with internally terminated receiver.
For example, 50Ω ANY-IN input. AC-coupling will
offset the output voltage by 200mV and this offset
voltage will be too low for proper driver operation. Any
unused output pair needs to be terminated when
VCCO is 1.2V, do not leave floating.
CML Output Termination with VCCO 1.8V, 2.5V
For VCCO of 1.8V, Figure 5a and Figure 5b,
terminate either with 50 ohms to VCCO or 100 ohms
differentially across the outputs. AC- or DC-coupling
is fine. For best signal integrity, terminate any unused
output pairs.
Input Termination
From 1.8V CML driver: Terminate input with VT tied to
1.8V. Don’t terminate 100 ohms differentially.
From 2.5V CML driver: Terminate input with either VT
tied to 2.5V or 100 ohms differentially.
The input cannot be DC-coupled from a 1.2V CML
driver.
Input AC-Coupling
The SY56020R input can accept AC-coupling from
any driver. Bypass VT with a 0.1µF low-ESR capacitor
to VCC as shown in Figures 4c and 4d. VT has an
internal high impedance resistor divider as shown in
Figure 2a, to provide a bias voltage for AC-coupling.
Timing Diagrams
Figure 1. Propagation Delay
Figure 1. Propagation Delay
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Typical Characteristics
VCC = 2.5, VCCO = 1.2V, GND = 0V, VIN = 400mV, RL = 50Ω to 1.2V, Data Pattern: 223-1, TA = 25°C, unless otherwise stated.
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Input and Output Stage
Figure 2a. Simplified Differential Input Buffer Figure 2b. Simplified CML Output Buffer
Single-Ended and Differential Swings
Figure 3a. Single-Ended Swing Figure 3b. Differential Swing
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Input Interface Applications
Figure 4a. CML Interface
(DC-Coupled, 1.8V, 2.5V)
Option: May connect VT to VCC
Figure 4b. CML Interface
(DC-Coupled, 1.8V, 2.5V)
Figure 4c. CML Interface
(AC-Coupled)
Figure 4d. LVPECL Interface
(AC-Coupled)
Figure 4e. LVPECL Interface
(DC-Coupled)
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CML Output Termination
Figure 5a. 1.2V, 1.8V or 2.5V
CML DC-Coupled Termination
Figure 5b. 1.8V or 2.5V
CML DC-Coupled Termination
Figure 5c. CML AC-Coupled Termination
(VCCO 1.8V or 2.5V)
Figure 5d. CML AC-Coupled Termination
(VCCO 1.2V only)
Related Product and Support Documents
Part Number Function Datasheet Link
HBW Solutions New Products and
Termination Application Notes http://www.micrel.com/page.do?page=/product-info/as/HBWsolutions.shtml
or (408) 955-1690
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Package Information
16-Pin QFN
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. This
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specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual
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whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties
relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right
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