VITESSE VSC7990W Datasheet
VITESSE
SEMICONDUCTOR CORPORATION
Advance Product Information
VSC7990
SONET/SDH 10.7Gb/s
Laser Diode Driver
G52303-0, Rev 2.2 Page 1
04/05/01
© 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 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 precision monitoring and setting of the current levels. Clock and data inputs are differentially terminated to 50
Ω and
must be AC-coupled. The superl at ive edge- rat e and dr iv e cur re nt of t he VSC7990 enables efficient design of an
OC-192/STM-64 transmitter using di rect ly modul at ed lase r diod es. A two- chi p OC-12 to OC-1 92 opti cal 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
• 100mA Available Modulation Current
• 100mA Available Bias Current
• 10.7Gb/s Operation
• Duty Cycle Control
• Single Power Supply
• Direct Access to Modulation and Bias FETs
• On-chip Reclocking Register
• On-chip MUX for Selectable Clocked or Unclocked
Applications
• On-chip 50
Ω Input Termination for Clock and Data
• Av ailab le in Tested Bare Die
50Ω
(2)
D
MUX
Q
DIN
PWN
PWP
VTHD
(1)
50Ω
(2)
NDIN
VTHDN
(1)
50Ω
(2)
(2)
CLK
NCLK
I
MOD
VIB
3Ω
VIP
CLKSEL
MIP
I
BIAS
MIB
IOUT
NIOUT
IBIAS
NOTES: (1) Terminated to off-chip capacitor. (2) On-die components.
3Ω
50Ω
(2)
(2)
VITESSE
SEMICONDUCTOR CORPORATION
Advance Product Inf ormation
VSC7990
SONET/SDH 10.7Gb/s
Laser Diode Driver
Page 2 G52303-0, Rev 2.2
04/05/01
© VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012
Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com
Internet: www.vitesse.com
AC Characteristics (Over recommended operating conditions)
Table 1: High-Speed Inputs and ECL Outputs
Table 2: Laser Driver AC Electrical Specifications
DC Characteristics (Over recommended operating conditions)
Table 3: Power Dissipat ion
Table 4: Laser Driver DC Electrical Specifications
Symbol Parameter Min Typ Max Units Conditions
V
IN
Single-ended Input Voltage Swing 400 1000 mVp-p V
CM
= −3.7V
V
IN
On-Chip Terminations 35 65 Ω
Symbol Parameter Min Typ Max Units Conditions
tR, t
F
Output Rise and Fall Times 35 ps
RL = 25Ω, 20% to 80%,
20mA < I
MOD
< 100mA
t
SU
Data to Clock Setup Time TBD ps
t
H
Hold Time TBD ps
Symbol Parameter Min Typ Max Units Conditions
I
VSS
Power Supply Current (VSS) 150 mA VSS = −5.5V, I
MOD
= I
BIAS
= 0mA
P
D
Total Power Dissipation 800 mW VSS = −5.5V, I
MOD
= I
BIAS
= 0mA
Symbol Parameter Min Typ Max Units Conditions
I
BIAS
Programmable Laser Bias Current 2 100 mA
I
MOD
Programmabl e Mo du la tio n Cur re nt 1 100 mA
V
IB
Laser Bias Contr ol Voltage VSS+2.1V V I
BIAS
= 60mA
V
IP
Laser Modulation Control Voltage VSS+2.1V V I
MOD
= 100mA
V
OCM
Output Voltage Compliance GND −3V VV
SS
= −5.2V
VITESSE
SEMICONDUCTOR CORPORATION
Advance Product Information
VSC7990
SONET/SDH 10.7Gb/s
Laser Diode Driver
G52303-0, Rev 2.2 Page 3
04/05/01
© VITESSE SEMICONDUCTOR CORPORATION • 741 Calle Plano • Camarillo, CA 93012
Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com
Internet: www.vitesse.com
Table 5: MUX Select Logic Table
Table 6: MOD_EN Logic Table
Absolute Maximum Ratings
(1)
Negative Power Supply Voltage (VSS)...........................................................................................................-6.0V
All Pins............................................... ........ .......................................................................................V
SS
to + 0.5V
Supply Voltage (V
SS
) .....................................................................................................................................-6.0V
Supply Current (I
SS
)....................................................................................................................................300mA
Input Voltage (V
IN
).............................................................................................................................VSS to +0.5V
Modulation Control Voltage (V
IP
)......................................................................................................VSS to +0.5V
Maximum Junction Temperature Range ......................................................................................-55°C to +125°C
Storage Temperature Range .........................................................................................................-65°C to +150°C
NOTE: (1) CAUTION: Stresses listed under “Absolute Maximum Ratings” may be applied to devices one at a time without caus-
ing permanent damage. Functionality at or above the values listed is not implied. Exposure to these values for extended
periods may affect device reliability.
Recommended Operating Conditions
Positive Voltage Rail (GND, VDD)..................................................................................................................... 0V
Negative Voltage Rail (V
SS
).............................................................................................................-5.5V to -4.9V
Junction Temperature Operating Range (T
J
) ...................................................................................0°C to +125°C
SEL
Mode Select
V
SS
Clocked Data In
GND (V
DD
) Unclocked Data In
N/C Unclocked Data In
SEL
Mode Select
V
SS
Modulation Current Enabled
GND (V
DD
) Modulation Current Disabled
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