1
Precision Edge®
SY58028U
Micrel, Inc.
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
DESCRIPTION
■Selects 1 of 4 differential inputs
■Provides two copies of the selected input
■Guaranteed AC performance over temperature and
voltage:
•DC-to- > 10.7Gbps data rate throughput
•<350ps IN-to-Out tpd
•<60ps tr/t
f times
■Ultra low-jitter design:
•<10psPP total jitter (clock)
•<1psRMS random jitter
•<10psPP deterministic jitter
•< 0.7psRMS crosstalk-induced jitter
■Unique patended input design minimizes crosstalk
■Accepts an input signal as low as 100mV
■Unique patended input termination and VT pin
accepts DC- and AC-coupled inputs (CML, LVPECL,
LVDS)
■Internal 50Ω output source termination
■400mV CML output swing (RL = 50Ω)
■Power supply 2.5V ±5% or 3.3V ±10%
■–40°C to +85°C temperature range
■Available in 32-pin (5mm ××
××
× 5mm) MLF® package
FEATURES
ULTRA PRECISION DIFFERENTIAL
CML 4:1 MUX WITH 1:2 FANOUT
AND INTERNAL I/O TERMINATION
Precision Edge®
SY58028U
APPLICATIONS
■Redundant clock and/or data distribution
■All SONET/SDH clock/data distribution
■Loopback
■All Fibre Channel distribution
■All Gigabit Ethernet clock and/or data distribution
Rev.: D Amendment: /0
Issue Date: August 2007
The SY58028U is a 2.5V/3.3V precision, high-speed, 4:1
differential CML multiplexer capable of handling clocks up
to 7GHz and data streams up to 10.7Gbps. In addition, a
1:2 fanout buffer provides two copies of the selected inputs.
The differential input includes Micrel’s unique, 3-pin input
termination architecture that allows customers to interface to
any differential signal (AC- or DC-coupled) as small as 100mV
without any level shifting or termination resistor networks in
the signal path. The result is a clean, stub-free, low-jitter
interface solution. The outputs are 50Ω source terminated
CML, with extremely fast rise/fall times guaranteed to be less
than 60ps.
The SY58028U operates from a 2.5V ±5% supply or a
3.3V ±10% supply and is guaranteed over the full industrial
temperature range of –40°C to +85°C. For applications that
require LVPECL outputs, consider the SY58029U or
SY58030U Multiplexers. The SY58028U is part of Micrel’s
high-speed, Precision Edge® product line.
All support documentation can be found on Micrel’s web
site at www.micrel.com.
TYPICAL PERFORMANCE
Precision Edge is a registered trademark of Micrel, Inc.
Micro
LeadFrame and MLF are registered trademarks of Amkor Technology, Inc.
Precision Edge®
FUNCTIONAL BLOCK DIAGRAM
IN0
/IN0
V
T0
50Ω
50Ω
IN1
/IN1
V
T1
50Ω
50ΩQ0
/Q0
0
1
MUX
4:1
MUX
1:2
Fanout
V
REF-AC0
IN2
/IN2
V
T2
50Ω
50Ω
V
REF-AC2
V
REF-AC1
2
IN3
/IN3
V
T3
50Ω
50Ω
V
REF-AC3
3
SEL0 (CMOS/TTL)
SEL1 (CMOS/TTL)
Q1
/Q1
TIME (100ps/div.)
Output Swing
(100mV/div.)
2
Precision Edge®
SY58028U
Micrel, Inc.
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
PACKAGE/ORDERING INFORMATION
Pin Number Pin Name Pin Function
1, 4 IN0, /IN0 Differential Inputs: These inputs accept AC- or DC-coupled signals as small as 100mV.
5, 8 IN1, /IN1 Each pin of a pair internally terminates to a VT pin through 50Ω. Note that these
25, 28 IN2, /IN2 inputs will default to an indeterminate state if left open. If an input pair is not used, connect
29, 32 IN3, /IN3 one input of the pair to ground through a 1kΩ resistor and the complement to VCC through a
825Ω resistor. Unused VT and VREF-AC may also be left open. Please refer to the “Input
Interface Applications” section for more details.
2, 6, 26, 30 VT0, VT1 Input Termination Center-Tap: Each side of the differential input pair terminates to a VT
VT2, VT3 pin. The VT pin provides a center-tap to the termination network for maximum
interface flexibility. See “Input Interface Applications” section for more details.
15, 18 SEL0, SEL1 This single-ended TTL/CMOS compatible input selects the inputs to the multiplexer. Note
that this input is internally connected to a 25kΩ pull-up resistor and will default to a logic
HIGH state if left open. Input logic threshold is VCC/2. See “Truth Table” for select control.
14, 19 NC No Connect.
10, 13, 16 VCC Positive Power Supply: Bypass with 0.1µF0.01µF low ESR capacitors.
17, 20, 23
11, 12 /Q0, Q0 Differential Outputs: These CML output pairs are copies of the selected input. Unused
21, 22 /Q1, Q1 output pairs may be left floating. See “Output Interface” section for termination guidelines.
9, 24 GND, Ground. Ground pin and exposed pad must be connected to the same ground plane.
Exposed Pad
3, 7, 27, 31 VREF-AC0 Reference Voltage: This reference output is equivalent to VCC–1.4V. It is used for AC-coupled
VREF-AC1 inputs. When interfacing to AC input signals, connect VREF-AC directly to the VT pin and
VREF-AC2 bypass with 0.01µF low ESR capacitor to VCC. See “Input Interface Applications” section.
VREF-AC3 Maximum sink/source current is 0.5mA.
PIN DESCRIPTION
24
23
22
21
20
19
18
17
GND
VCC
Q1
/Q1
VCC
NC
SEL1
VCC
IN0
VT0
VREF-AC0
/IN0
IN1
VT1
VREF-AC1
/IN1
1
2
3
4
5
6
7
8
910111213141516
32 31 30 29 28 27 26 25
/IN2
IN3
VT3
VREF-AC3
/IN3
VREF-AC2
VT2
IN2
VCC
Q0
/Q0
VCC
GND
NC
SEL0
VCC
32-Pin MLF® (MLF-32)
TRUTH TABLE
SEL1 SEL0
00IN0 Input Selected
01IN1 Input Selected
10IN2 Input Selected
11IN3 Input Selected
Ordering Information(1)
Package Operating Package Lead
Part Number Type Range Marking Finish
SY58028UMI MLF-32 Industrial SY58028U Sn-Pb
SY58028UMITR(2) MLF-32 Industrial SY58028U Sn-Pb
SY58028UMG(3) MLF-32 Industrial SY58028U with Pb-Free
Pb-Free bar-line indicator NiPdAu
SY58028UMGTR(2, 3) MLF-32 Industrial SY58028Uwith Pb-Free
Pb-Free bar-line indicator NiPdAu
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 recommended for new designs.
3
Precision Edge®
SY58028U
Micrel, Inc.
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
Absolute Maximum Ratings(1)
Power Supply Voltage (VCC )...................... –0.5V to +4.0V
Input Voltage (VIN)......................................... –0.5V to VCC
CML Output Voltage (VOUT)........... VCC–1.0V to VCC+0.5V
Termination Current(3)
Source or sink current on VT pin ........................±100mA
Input Current
Source or sink current on IN, /IN pin ....................±50mA
Lead Temperature (soldering, 20 sec.) ..................... 260°C
Storage Temperature Range (TS )...........–65°C to +150°C
Operating Ratings(2)
Power Supply Voltage (VCC)............... +2.375V to +2.625V
............................................................ +3.0V to +3.6V
Ambient Temperature Range (TA) .............–40°C to +85°C
Package Thermal Resistance(4)
MLF® (θJA)
Still-Air .............................................................35°C/W
MLF® (ψJB)
Junction-to-Board ..............................................2°C/W
TA= –40°C to 85°C, unless otherwise stated.
Symbol Parameter Condition Min Typ Max Units
VCC Power Supply Voltage VCC = 2.5V 2.375 2.5 2.625 V
VCC = 3.3V 3.0 3.3 3.6 V
ICC Power Supply Current No load, max. VCC 120 150 mA
RDIFF_IN Differential Input Resistance
(IN-to-/IN)
80 100 120 Ω
RIN Input Resistance (IN-to-VT, /IN-to-VT)405060Ω
VIH Input HIGH Voltage
(IN-to-/IN)
Note 6 VCC–1.6 VCC V
VIL Input LOW Voltage
(IN-to-/IN)
0V
IH–0.1 V
VIN Input Voltage Swing
(IN-to-/IN)
See Figure 1a. 0.1 1.7 V
VDIFF_IN Differential Input Voltage Swing
(IN-to-/IN)
See Figure 1b. 0.2 V
VT IN Max Input Voltage (IN-to-VT)1.28 V
VREF-AC Reference Voltage VCC–1.3 VCC–1.2 VCC–1.1 V
Notes:
1. Permanent device damage may occur if ratings in the “Absolute Maximum Ratings” section 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. Due to the limited drive capability, use for input of the same package only.
4. Thermal performance assumes exposed pad is soldered (or equivalent) to the device’s most negative potential (GND) on the PCB. ψJB uses 4-layer
θJA in still air number unless otherwise stated.
5. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
6. VIH (min) not lower than 1.2V.
DC ELECTRICAL CHARACTERISTICS(5)
4
Precision Edge®
SY58028U
Micrel, Inc.
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
VCC = 2.5V ±5% or 3.3V ±10%; TA= -40°C to 85°C; RL = 100Ω across each output pair or equivalent; unless otherwise stated.
Symbol Parameter Condition Min Typ Max Units
VOH Output HIGH Voltage VCC–0.020 VCC V
VOUT Output Voltage Swing See Figure 1a. 325 400 mV
VDIFF_OUT Differential Output Voltage Swing See Figure 1b. 650 800 mV
ROUT Output Source Impedance 40 50 60 Ω
CML OUTPUT DC ELECTRICAL CHARACTERISTICS(7)
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 SEL0, SEL1 2.0 V
VIL Input LOW Voltage SEL0, SEL1 0.8 V
IIH Input HIGH Current 40 µA
IIL Input LOW Current –300 µA
Note:
7. The circuit is designed to meet the DC specifications shown in the above table after thermal equilibrium has been established.
LVTTL/CMOS DC ELECTRICAL CHARACTERISTICS(7)
5
Precision Edge®
SY58028U
Micrel, Inc.
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
SINGLE-ENDED AND DIFFERENTIAL SWINGS
V
IN
,
V
OUT
400mV (Typ.)
Figure 1a. Single-Ended Voltage Swing
V
DIFF_IN
,
V
DIFF_OUT
800mV (Typ.)
Figure 1b. Differential Voltage Swing
VCC = 2.5V ±5% or 3.3V ±10%; RL = 100Ω across each output pair, or equivalent; TA= –40°C to +85°C, VIN ≥ 100mV unless otherwise stated.
Symbol Parameter Condition Min Typ Max Units
fMAX Maximum Operating Frequency NRZ Data 10.7 Gbps
VOUT ≥ 200mV Clock 7 GHz
tpd Propagation Delay (Diff) (IN to Q) VIN ≥ 100mV 170 260 340 ps
(SEL to Q) 100 500 ps
tpd Tempco Differential Propagation Delay 115 fs/°C
Temperature Coefficient
tSKEW Output-to-Output Note 9 720ps
Part-to-Part Note 10 50 ps
tJITTER Data Random Jitter Note 11 2.5Gbps to 3.2Gbps 1 psRMS
Deterministic Jitter Note 12 2.5Gbps to 3.2Gbps 10 psPP
Clock Cycle-to-Cycle Jitter Note 13 1ps
RMS
Total Jitter Note 14 10 psPP
Crosstalk Induced Jitter Note 15 0.7 psRMS
(Adjacent Channel)
tr, tfOutput Rise/Fall Time 20% to 80%, Full output swing 20 45 60 ps
Notes:
8. High frequency AC electricals are guaranteed by design and characterization.
9. Output-to-output skew is measured between outputs under identical input conditions.
10. Part-to-part skew is defined for two parts with identical power supply voltages at the same temperature and with no skew of the edges at the
respective inputs.
11. Random jitter is measured with a K28.7 comma detect character pattern, measured at 2.5Gbps to 3.2Gbps.
12. Deterministic jitter is measured at 2.5Gbps to 3.2Gbps, with both K28.5 and 223–1 PRBS pattern.
13. Cycle-to-cycle jitter definition: the variation of periods between adjacent cycles, Tn–Tn–1 where T is the time between rising edges of the output
signal.
14. Total jitter definition: with an ideal clock input of frequency ≤fMAX, no more than one output edge in 1012 output edges will deviate by more than the
specified peak-to-peak jitter value.
15. Crosstalk is measured at the output while applying two similar clock frequencies that are asynchronous with respect to each other at the inputs.
AC ELECTRICAL CHARACTERISTICS(8)
6
Precision Edge®
SY58028U
Micrel, Inc.
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
TIMING DIAGRAMS
IN
/IN
Q
/Q
t
pd
t
pd
V
IN
V
OUT
Figure 2a. IN-to-Q Timing Diagram
SEL
Q
/Q
t
pd
t
pd
V
OUT
V
CC
/2 V
CC
/2
Figure 2b. SEL-to-Q Timing Diagram
SEL0 Q: SEL1 = LOW; IN0, /IN1 = LOW; /IN0, IN1 = HIGH
or: SEL1 = HIGH; IN2, /IN3 = LOW; /IN2, IN3 = HIGH
SEL1 Q: SEL0 = LOW; IN0, /IN2 = LOW; /IN0, IN2 = HIGH
or: SEL0 = HIGH; IN1, /IN3 = LOW; /IN1, IN3 = HIGH
7
Precision Edge®
SY58028U
Micrel, Inc.
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
FUNCTIONAL CHARACTERISTICS
VCC = 2.5V, GND = 0, VIN = 100mV, TA = 25°C, unless otherwise stated.
200MHz Output
TIME (600ps/div.)
Output Swing
(100mV/div.)
2GHz Output
TIME (70ps/div.)
Output Swing
(100mV/div.)
10.7Gbps Output (223
–
1 PRBS)
TIME (25ps/div.)
Output Swing
(100mV/div.)
TIME (100ps/div.)
Output Swing
(100mV/div.)
7Gbps Output (2
23
–
1 PRBS)
TIME (50ps/div.)
Output Swing
(100mV/div.)
8
Precision Edge®
SY58028U
Micrel, Inc.
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
TYPICAL OPERATING CHARACTERISTICS
VCC = 2.5V, GND = 0, VIN = 100mV, TA = 25°C, unless otherwise stated.
226
228
230
232
234
236
238
240
0 200 400 600 800 1000
PROPAGATION DELAY (ps)
INPUT VOLTAGE SWING (mV)
Propagation Delay
vs. Input Voltage Swing
0
0.2
0.4
0.6
0.8
1
1.2
-40 -20 0 20 40 60 80 100
∆ OUTPUT-to-OUTPUT SKEW (ps)
TEMPERATURE (°C)
Output-to-Output Skew
vs. Temperature
228
230
232
234
236
238
240
242
244
246
248
-60 -40 -20 0 20 40 60 80 100
PROPAGATION DELAY (ps)
TEMPERATURE (°C)
Propagation Delay
vs. Temperature
0
50
100
150
200
250
300
350
400
450
500
012345678910
OUTPUT AMPLITUDE (mV)
FREQUENCY (GHz)
Output Amplitude
vs. Frequency
9
Precision Edge®
SY58028U
Micrel, Inc.
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
INPUT STAGE
50Ω
50Ω
V
CC
GND
V
T
IN
/IN
Figure 3. Simplified Differential Input Stage
INPUT INTERFACE APPLICATIONS
LVDS IN
/IN
V
T
NC
SY58028U
V
CC
GND V
REF-AC
NC
Figure 4f. LVDS
Interface
CML IN
/IN
V
T
NC
SY58028U
V
CC
GND V
REF-AC
NC
Figure 4a. DC-Coupled CML
Interface
Option: May connect VT to VCC
LVPECL
IN
/IN
VT
SY58028U
VCC
VCC
NC
0.01µFRpd
GND VREF-AC
For a 3.3V system, Rpd = 50Ω
For a 2.5V system, Rpd = 19Ω
Figure 4c. DC-Coupled PECL
Interface
LVPECL
IN
/IN
VT
SY58028U
VCC
VCC
0.01µF
GND VREF-AC
Rpd
Rpd
For a 3.3V system, Rpd = 100Ω
For a 2.5V system, Rpd = 50Ω
Figure 4d. AC-Coupled LVPECL
Interface
CML IN
/IN
V
T
SY58028U
V
CC
V
CC
GND
0.01µFV
REF-AC
Figure 4b. CML Interface
(AC-Coupled)
10
Precision Edge®
SY58028U
Micrel, Inc.
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
Part Number Function Data Sheet Link
SY58028U Ultra Precision Differential CML 4:1 MUX http://www.micrel.com/product-info/products/sy58028u.shtml
with 1:2 Fanout and Internal I/O Termination
SY58029U Ultra Precision Differential LVPECL 4:1 MUX http://www.micrel.com/product-info/products/sy58029u.shtml
with 1:2 Fanout and Internal Termination
SY58030U Ultra Precision, 400mV Differential LVPECL 4:1 http://www.micrel.com/product-info/products/sy58030u.shtml
MUX with 1:2 Fanout and Internal Termination
MLF® Application Note www.amkor.com/products/notes_papers/MLF_AppNote_0902.pdf
HBW Solutions New Products and Applications www.micrel.com/product-info/products/solutions.shtml
RELATED MICREL PRODUCTS AND SUPPORT DOCUMENTATION
OUTPUT INTERFACE APPLICATIONS
50Ω50Ω
VCC
GND
/Q
Q
100Ω
SY58028U
16mA
ZO = 50Ω
ZO = 50Ω
Figure 5a. CML DC-Coupled
(100Ω Termination)
50Ω50Ω
VCC
GND
/Q
Q
50Ω
SY58028U
50Ω
DC bias
per application
16mA
ZO = 50Ω
ZO = 50Ω
Figure 5b. CML AC-Coupled
(50Ω Termination)
11
Precision Edge®
SY58028U
Micrel, Inc.
M9999-082707
hbwhelp@micrel.com or (408) 955-1690
32-PINMicroLeadFrame® (MLF-32)
Package
EP- Exposed Pad
Die
CompSide Island
Heat Dissipation
Heavy Copper Plane
Heavy Copper Plane
VEE
VEE
Heat Dissipation
PCB Thermal Consideration for 32-Pin MLF® Package
(Always solder, or equivalent, the exposed pad to the PCB)
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL + 1 (408) 944-0800 FAX + 1 (408) 474-100 WEB http://www.micrel.com
The information furnished by Micrel in this data sheet 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 specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into
the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s
use or sale of Micrel Products for use in life support appliances, devices or systems is at Purchaser’s own risk and Purchaser agrees to fully indemnify
Micrel for any damages resulting from such use or sale.
© 2005 Micrel, Incorporated.
Package Notes:
1. Package meets Level 2 qualification.
2. All parts dry-packaged before shipment.
3. Exposed pads must be soldered to a ground for proper thermal management.
