VITESSE
SEMICONDUCTOR CORPORATION
Advance Product Information
VSC7961
Features
3.125Gb/s PECL Limiting Amplifier with LOS Detect
Applications
• 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
• 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
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
VSC7961
V
CC
8k
Ω
LOS
V
CC
8k
Ω
TH
RMS Power
Detect and
Control
IN+
LOS
SQUELCH
Output Control
LEVEL
OUT+
100Ω
IN-
OUT-
Lowpass Filter
10pF
CZ1
CZ2
Offset Correction
G52360-0, Rev 2.0
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
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