SY54020R

Low Voltage 1.2V/1.8V/2.5V CML 1:4 Fanout

Buffer with /EN and Fail-Safe Input

3.2Gbps, 2.5GHz

Precision Edge is a registered trademark of Micrel, Inc.

MLF and MicroLeadFrame are registered trademarks of Amkor Technology.

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com

April 2009

M9999-041409-A

General Description

The SY54020R is a fully differential, low voltage

1.2V/1.8V/2.5V CML 1:4 Fanout Buffer with active-low

Enable (/EN) and Fail-Safe Input (FSI). The Enable is

synchronous

so

that

the

outputs

will

only

be

enabled/disabled when they are already in the LOW

state. This avoids any chance of generating a runt clock

pulse when the device is enabled/disabled as can

happen with an asynchronous control. When this device

is used as a clock fanout, disabling the downstream

clock may reduce system power. FSI is a special circuit

designed to sense the amplitude of the input signal and

to latch the output when an invalid or no signal is

present at the input. The SY54020R can process clock

signals up to 2.5 GHz or data patterns up to 3.2Gbps.

The differential input includes Micrel’s unique, 3-pin

input termination architecture that interfaces to LVPECL,

LVDS or CML differential signals as small as 100mV

resistor networks in the signal path. For AC-coupled

input

interface

applications,

an

internal

voltage

CML, with extremely fast rise/fall times guaranteed to be

less than 100ps.

The SY54020R 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).

Datasheets and support documentation can be found on

Functional Block Diagram

Precision Edge

®

Features

• 1.2V/1.8V/2.5V CML 1:4 Fanout Buffer with FSI

• Active-low Enable (/EN) input to disable the outputs

• Guaranteed AC performance over temperature and

voltage:

– DC-to > 3.2Gbps Data throughput

– DC-to > 2.5GHz Clock throughput

– <400 ps propagation delay (IN-to-Q)

– <20ps within-device skew

– <100 ps rise/fall times

• Ultra-low jitter design

• High-speed CML outputs

• 2.5V ±5% V

operation

• Industrial temperature range: –40°C to +85°C

Applications

• SONET clock and data distribution

• Fibre Channel clock and data distribution

• Gigabit Ethernet clock and data distribution

Markets

• Storage

• ATE

• Test and measurement

• Enterprise networking equipment

• High-end servers

• Access

• Metro area network equipment