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.)