VITESSE

SEMICONDUCTOR CORPORATION

Advance Product Information

VSC7961

3.125Gb/s PECL Limiting Amplifier with LOS Detect

G52360-0, Rev 2.0

Page 1

02/09/01

© 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

Applications

General Description

The VSC7961 is a single-supply limiting amplifier with Loss of Signal (LOS) detect for SONET/SDH and

Fibre Channel applications up to 3.125Gb/s. The VSC7961 provides a constant output signal swing for a wide

range of input voltages and has Positive Emitter-Coupled Logic (PECL). The VSC7959 provides the same func-

tionality as the VSC7961 with Current-Mode Logic (CML) outputs. Key features of the VSC7961 are its RMS

power detectors for programmable LOS detection, optional output squelch, adjustable output levels, excellent

jitter performance, and fast edge rates. The VSC7961 is available in die form or in a TSSOP-16 package.

Block Diagram

• 3.3V or 5V Power Supply

• Typical Supply Current of 32mA

• Positive Emitter-Coupled Logic (PECL) Outputs

• Optional Output Squelch

• Loss of Signal Detect

• Output Offset Correction

• Rise/Fall Times Faster than 100ps

• Packages: TSSOP-16, Bare Die

VSC7961

100

Ω

IN+

IN-

RMS Power

Detect and

Control

Lowpass Filter

10pF

Offset Correction

8k

Ω

Output Control

8k

Ω

LOS

SQUELCH

LEVEL

OUT+

OUT-

LOS

CZ1

CZ2

TH

• SONET/SDH at 622Mb/s, 1.244Gb/s, 2.488Gb/s,

and 3.125Gb/s

• Full-Speed Fibre Channel (1.062Gb/s)

• Small Form Factor (SFF) Receivers

• ATM Optical Receivers