SY87729L

3.3V AnyClock

Fractional N Synthesizer

AnyClock and AnyRate are registered trademarks of Micrel, Inc.

MicroWire is a trademark of National Semiconductor

Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (

General Description

The SY87729L is a complete rate independent frequency

synthesizer integrated circuit. From a single reference

source, this device generates a differential PECL

reference frequency for Micrel's SY87721L 10Mbps to

2.7Gbps combined CDR and CMU.

The SY87729L generates an exactly correct reference

frequency for common data transport protocols. This is

especially important in transponder applications, where a

standards compliant protocol data unit must be generated

downstream, even in the absence of any signal from the

associated upstream interface.

In addition, SY87729L will generate exactly correct

reference frequencies for common data transport protocols

augmented by forward error correction codes.

For proprietary applications, the SY87729L generates

reference frequencies guaranteed to enable the SY87721L

CDR to lock to any possible baud rate in its range.

SY87729L accepts configuration via a MicroWire™

interface.

Data sheets and support documentation can be found on

Micrel’s web site at: www.micrel.com.

AnyClock

®

Features

• Fractional synthesizer from 10MHz to 365MHz from a

single 27MHz reference oscillator

• Generates exactly the correct frequency for common

transport protocols with or without FEC

• Directly enables SY87721L to lock onto any data rate

within its range

• Exceeds BellCore and ITU jitter generation

specifications

• Programmable via MicroWire™ interface

• Available in 32-Pin EPAD-TQFP package

Applications

• Metro access system

• Transponders

• Multiplexers: access, add drop mux

• SONET/SDH/ATM-based transmission systems,

modules and test equipment

• Broadband cross-connects

• Fiber optic test equipment

• Protocols supported:

−

OC-1, OC-3, OC-12, OC-48, ATM, Gigabit Ethernet,

Fast Ethernet, Fibre Channel, 2X Fibre Channel,

1394, InfiniBand, Proprietary Optical Transport

July 2011

M9999-072111-G