1

SY58021U

Micrel, Inc.

M9999-062405

hbwhelp@micrel.com or (408) 955-1690

DESCRIPTION

Precision 1:4, LVPECL fanout buffer

Guaranteed AC performance over temperature/

voltage:

• <15ps max skew

Low jitter performance

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

–40

Available in 16-pin (3mm

××××× 3mm) MLF™ package

FEATURES

4GHz, 1:4 LVPECL FANOUT

BUFFER/ TRANSLATOR

WITH INTERNAL TERMINATION

SY58021U

APPLICATIONS

s All SONET and All GigE clock distribution

s Fibre Channel clock and data distribution

s Backplane distribution

s High-end, low skew, multiprocessor synchronous

clock distribution

Rev.: D

Amendment: /0

Issue Date:

June 2005

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

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

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

product line.

All support documentation can be found on Micrel’s web

site at www.micrel.com.

FUNCTIONAL BLOCK DIAGRAM

TYPICAL PERFORMANCE

Precision Edge is a registered trademark of Micrel , Inc.

MicroLeadFrame and MLF are trademarks of Amkor Technology, Inc.

IN

/IN

Q1

/Q1

Q0

/Q0

50

Ω

50

Ω

Q3

/Q3

Q2

/Q2

1.25GHz Output

TIME (100ps/div.)