VITESSE
SEMICONDUCTOR CORPORATION
Preliminary Data Sheet
VSC7927
Features
• Rise Times of Less Than 100ps
• High Speed Operation
(Up to 2.5 Gb/s NRZ Data)
• Differential or Single-Ended Inputs
• Single Supply
• ECL-Compatible Clock and Data Inputs
SONET/SDH 2.5Gb/s Laser Diode Driver
• Direct Access to Modulation and Bias FETs
• Data Density Monitors
• On-Chip Reclocking Register
• On-Chip Mux for Clocked or Non-clocked Appli-
cations
• On-Chip 50
Ω
Input Termination: Clock and Data
General Description
The VSC7927 is a single 5V supply, 2.5 Gb/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 monitor-
ing and setting of the current levels. Data density outputs are provided to allow the user to adjust the laser bias
in high unbalanced data applications. Clock and data inputs are differentially terminated to 50
Ω
.
Applications
• SDH/SONET @ 622Mb/s, 1.244Gb/s, 2.488Gb/s
• Full Speed Fibre Channel (1.062Gb/s)
VSC7927 Block Diagram
MK
NMK
IOUT
NIOUT
DIN
50
Ω
**
DINTERM*
50
Ω
**
NDIN
D Q
M
U
X
IBIAS
DCC
CLK
50
Ω
**
CLKTERM*
50
Ω
**
NCLK
SEL
MIP
*Terminated to Off-chip Capacitor
**On Die Components
VIB
VIP
I
MOD
I
BIAS
MIB
G52201-0, Rev 3.0
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
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