VITESSE
SEMICONDUCTOR CORPORATION
Advance Product Information
VSC7990
Features
• Typical Rise Times of 25ps
• 100mA Available Modulation Current
• 100mA Available Bias Current
• 10.7Gb/s Operation
• Duty Cycle Control
• Single Power Supply
SONET/SDH 10.7Gb/s
Laser Diode Driver
• Direct Access to Modulation and Bias FETs
• On-chip Reclocking Register
• On-chip Mux for Selectable Clocked or Non-
clocked Applications
• On-chip 50Ω Input Termination for Clock and Data
• Available in Tested Bare Die (Know as Good Die)
General Description
The VSC7990 is a single +5V or
−5.2V
supply, 10.7Gb/s laser diode driver with direct access to the laser
modulation and bias FETs. Laser bias and modulation currents are set by external components allowing preci-
sion monitoring and setting of the current levels. Clock and data inputs are differentially terminated to 50Ω. The
superlative edge-rate and drive current of the VSC7990 enables efficient design of an OC-192/STM-64 trans-
mitter using directly modulated laser diodes. A two-chip OC-12 to OC-192 optical transmitter can be easily
implemented using the VSC7990 and the VSC8171 10Gb/s MUX/CRU.
Applications
• OC-192/STM-64 @ 2.488Gb/s to 10.7Gb/s
• 10Gb/s Serial Ethernet
VSC7990 Block Diagram
PWN
PWP
DIN
50Ω
(2)
VTHD
(1)
NDIN
50Ω
(2)
VTHDN
(1)
CLKSEL
CLK
50Ω
(2)
(2)
IOUT
D
Q
MUX
NIOUT
IBIAS
IMOD
IBIAS
VIP
NCLK
50Ω
(2)
(2)
VIB
NOTES: (1) Terminated to off-chip capacitor. (2) On-die components.
MIP
MIB
G52303-0, Rev 2.0
12/15/00
©
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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