VITESSE
SEMICONDUCTOR CORPORATION
Advance Product Information
VSC7959
Features
• 3.3V or 5V Power Supply
• Typical Supply Current of 32mA
• Current-Mode Logic Outputs
• Optional Output Squelch
• Loss of Signal Detect
• Output Offset Correction
• Rise/Fall Times Faster than 100ps
• Packages: TSSOP-16, Bare Die
3.125Gb/s CML 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
General Description
The VSC7959 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 VSC7959 provides a constant output signal swing for a wide
range of input voltages and has Current-Mode Logic (CML) outputs. The VSC7961 provides the same function-
ality as the VSC7959 with positive emitter-coupled logic (PECL) outputs. Key features of the VSC7959 are its
RMS power detectors for programmable LOS detection, optional output squelch, adjustable output levels,
excellent jitter performance, and fast edge rates. The VSC7959 is available in die form or in a TSSOP-16 pack-
age.
Block Diagram
VSC7959
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
G52358-0, 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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