SY89468U

Precision LVDS 1:20 Fanout with 2:1 MUX

and Internal Termination with Fail-Safe Input

Precision Edge is a registered trademark of Micrel, Inc.

MicroLeadFrame and MLF are registered trademarks of Amkor Technology, Inc.

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

November 2008

M9999-110308-D

General Description

The SY89468U is a 2.5V, 1:20 LVDS fanout buffer

with a 2:1 differential input multiplexer (MUX). A

unique Fail-Safe Input (FSI) protection prevents

metastable output conditions when the selected

input clock fails to a DC voltage (voltage between

the pins of the differential input drops significantly

below 100mV).

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

internal termination architecture that can interface to

any differential signal (AC- or DC-coupled) as small

termination resistor networks in the signal path. The

outputs are LVDS compatible with very fast rise/fall

times guaranteed to be less than 270ps.

The SY89468U operates from a 2.5V ±5% supply

and is guaranteed over the full industrial

temperature range of –40°C to +85°C. The

SY89468U is part of Micrel’s high-speed, Precision

Edge

All support documentation can be found on Micrel’s

Functional Block Diagram

Precision Edge

®

Features

∑ Selects between two inputs, and provides 20

precision LVDS copies

∑ Fail-Safe Input

– Prevents outputs from oscillating when input is

invalid

∑ Guaranteed AC performance over temperature and

supply voltage:

– DC to >1.5GHz throughput

– < 1200ps Propagation Delay (In-to-Q)

– < 270ps Rise/Fall times

∑ Ultra-low jitter design:

∑ Unique, patented MUX input isolation design

minimizes adjacent channel crosstalk

∑ Unique, patented internal termination and VT pin

accepts DC- and AC-coupled inputs (CML, PECL,

LVDS)

∑ Wide input voltage range VCC to GND

∑ 2.5V ±5% supply voltage

∑ -40°C to +85°C industrial temperature range

∑ Available in 64-pin EPAD-TQFP package

Applications

∑ Fail-safe clock protection

∑ Ultra-low jitter LVDS clock or data distribution

∑ Rack-based Telecom/Datacom

Markets

∑ LAN/WAN

∑ Enterprise servers

∑ ATE

∑ Test and measurement