VITESSE
SEMICONDUCTOR CORPORATION
SONET/SDH 3.125Gb/s
Laser Diode Driver with Automatic Power Control
Preliminary Data Sheet
VSC7940
Electrical Characteristics
Table 1: AC Specifications
AC specifications are guaranteed by design and characterization. Typical values are for 5V operation.
Symbol
t
SU
t
H
Parameter
Input Latch Setup Time
Input Latch Hold Time
Enable/Start-up Delay
Min
100
100
Typ
Max
Units
ps
ps
Conditions
LATCH=high
LATCH=high
250
TBD
TBD
10
80
7
20
TBD
TBD
50
ns
ps
ps
ps
bits
ps
p-p
Jitter BW=12kHz to 20MHz,
0-1 pattern.
20% to 80%
20% to 80%
See Notes 1, 2
t
R
t
F
PWD
CID
MAX
t
J
Output Rise Time
Output Fall Time
Pulse Width Distortion
Maximum Consecutive Identical Digits
Jitter Generation
NOTES: (1) Measured with 622Mb/s 0-1 pattern, LATCH=high. (2) PWD = (wider pulse - narrower pulse) / 2).
Table 2: DC Specifications
Symbol
V
SS
I
CC
I
BIAS
I
BIAS-OFF
S
BIAS
Parameter
Power Supply Voltage
Power Supply Current
Bias Current Range
Bias Off Current
Bias Current Stability
Bias Current Absolute Accuracy
Min
4.75
Typ
5.0
TBD
Max
5.25
45
100
100
Units
V
Conditions
R
MODSET
=7.3kΩ
mA
mA
µA
ppm/°C
%
V
1000
-50
90
-15
5
15
100
200
±15
480
µA
ppm/°C
%
mA
µA
%
ENABLE=low or
DISABLE=high
(1)
See Note 2
I
MD
=1mA
(2)
I
MD
=18µA
(2)
Refers to part-to-part variation
R
BIASMAX
=4.8kΩ
I
BIAS
and I
MOD
excluded, V
CC
=5V
Voltage at BIAS pin=(V
CC
-1.6)
ENABLE=low or
DISABLE=high
(1)
APC open loop. I
BIAS
=100mA
APC open loop. I
BIAS
=1mA
Refers to part-to-part variation
1
230
900
±15
1.5
18
-480
VR
MD
I
MD
Monitor Diode Reverse Bias Voltage
Monitor Diode Reverse Current Range
Monitor Diode Bias Setpoint Stability
Monitor Diode Bias Absolute Accuracy
I
MOD
Modulation Current Range
I
MOD-OFF
Modulation Off Current
Modulation Current Absolute Accuracy
Page 2
©
VITESSE
SEMICONDUCTOR CORPORATION
• 741 Calle Plano • Camarillo, CA 93012
Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com
Internet: www.vitesse.com
G52357-0, Rev 3.2
05/11/01
VITESSE [ VITESSE SEMICONDUCTOR CORPORATION ]
