VITESSE

SEMICONDUCTOR CORPORATION

Multi-Rate SONET/SDH

Clock and Data Recovery IC

Data Sheet

VSC8122

G52228-0, Rev 4.1

Page 1

01/05/01

© VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012

Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com

Internet: www.vitesse.com

Features

General Description

The VSC8122 is a single-chip clock recovery IC for use in SONET OC-48, OC-24, OC-12, OC-3, or Giga-

bit Ethernet systems operating at their respective 2.48832Gb/s, 1.24416Gb/s, 622.08Mbps, 155.52Mbps, or

1.25Gbps data rates. The VSC8122 complies with SONET jitter tolerance, jitter transfer and jitter generation

specifications.

Alarm functions support typical telecom system applications. The Loss of Lock (LOL) output indicates

when the device goes out of lock, which would most often occur in the event of a loss of valid data. The NOREF

output flags when the reference input to the VSC8122 either is removed, or goes severely out of tolerance.

VSC8122 Block Diagram

• Multi-Rate OC-3, OC-12, OC-24, OC-48 Clock

and Data Recovery

• Supports Gigabit Ethernet

• Differential Back Terminated I/O

• Maintains Clock Output in the Absence of Data

• Selectable Reference Clock

• Loss of Lock Indicator

• Exceeds SONET/SDH Requirements for Jitter

Tolerance, Jitter Transfer and Jitter Generation.

• 3.3V Supply Operation

• 1W Typical Power

• 64-pin , 10x10mm PQFP Packaging

DI+

DI-

Ph/Freq.

Detector

Loop

Filter

VCO

Data

Retiming

Lock

Detect

CO+

CO-

DO+

DO-

LOL

NOREF

REFCK1 +/-

REFCK0 +/-

REF_SEL[1:0]

REF_INPUTSEL

FSEL[1:0]

Divider

Divider

FILTI+/-

FILTO+/-