Micrel, Inc.
4GHz, 1:4 LVPECL FANOUT
BUFFER/ TRANSLATOR
WITH INTERNAL TERMINATION
Precision Edge
®
SY58021U
Precision Edge
®
SY58021U
FEATURES
Precision 1:4, LVPECL fanout buffer
Guaranteed AC performance over temperature/
voltage:
• >4GHz f
MAX
(clock)
• <100ps t
r
/ t
f
Times
• <300ps t
pd
• <15ps max skew
Low jitter performance
• <10ps
pp
total jitter (clock)
• <1ps
rms
random jitter (data)
• <10ps
pp
deterministic jitter (data)
Accepts an input signal as low as 100mV
Unique input termination and VT pin accepts
DC-coupled and AC-coupled differential inputs:
LVPECL, LVDS, and CML
100k LVPECL compatible 800mV swing output
Power supply 2.5V
±
5% and 3.3V
±
10%
–40
°
C to +85
°
C temperature range
Available in 16-pin (3mm
×
3mm) MLF
®
package
Precision Edge
®
DESCRIPTION
The SY58021U is a 2.5V/3.3V precision, high-speed, fully
differential 1:4 LVPECL fanout buffer. Optimized to provide
four identical output copies with less than 15ps of skew and
less than 10ps
pp
total jitter, the SY58021U can process
clock signals as fast as 4GHz.
The differential input includes Micrel’s unique, 3-pin input
termination architecture interfaces to differential LVPECL,
CML, and LVDS signals (AC- or DC-coupled) as small as
100mV without any level-shifting or termination resistor
networks in the signal path. For AC-coupled input interface
applications, an on-board output reference voltage (V
REF-
AC
) is provided to bias the VT pin. The outputs are 100k
LVPECL compatible, with extremely fast rise/fall times
guaranteed to be less than 100ps.
The SY58021U operates from a 2.5V
±5%
supply or
3.3V
±10%
supply and is guaranteed over the full industrial
temperature range (–40°C to +85°C). For applications that
require faster rise/fall times, or greater bandwidth, consider
the SY58022U 1:4 fanout buffer with 400mV LVPECL output
swing, or the SY58020U 1:4 CML fanout buffer. The
SY58021U 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.
APPLICATIONS
s
s
s
s
All SONET and All GigE clock distribution
Fibre Channel clock and data distribution
Backplane distribution
High-end, low skew, multiprocessor synchronous
clock distribution
FUNCTIONAL BLOCK DIAGRAM
IN
50Ω
V
T
50Ω
/IN
V
REF-AC
TYPICAL PERFORMANCE
Q0
/Q0
1.25GHz Output
Q1
(200mV/div.)
Amplitude
/Q1
Q2
/Q2
Q3
/Q3
Precision Edge is a registered trademark of Micrel , Inc.
MicroLeadFrame
and MLF are registered trademarks of Amkor Technology, Inc.
M9999-020207
hbwhelp@micrel.com or (408) 955-1690
TIME (100ps/div.)
Rev.: E
Amendment: /0
1
Issue Date: February 2007
MICREL [ MICREL SEMICONDUCTOR ]
