SY89468U Datasheet, PDF (1/15 Pages) Micrel Semiconductor – Precision LVDS 1:20 Fanout with 2:1 MUX and Internal Termination with Fail-Safe Input

SY89468U
Precision LVDS 1:20 Fanout with 2:1 MUX
and Internal Termination with Fail-Safe Input
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
as 100mV (200mV_PP) without any level shifting or
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^® product line.
All support documentation can be found on Micrel’s
web site at: www.micrel.com.
Functional Block Diagram
Features
Precision Edge^®
∑ 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:
– <1ps_RMS random jitter
– <1ps_RMS cycle-to-cycle jitter
– <10ps_PP total jitter (clock)
– <0.7ps_RMS MUX crosstalk induced jitter
∑ 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
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 [phone] • fax + 1 [phone] • http://www.micrel.com
November 2008
M9999-110308-D
[e-mail] or [phone]