CXB1818Q Datasheet, PDF (1/17 Pages) Sony Corporation – Laser Diode Driver

Laser Diode Driver
CXB1818Q
Description
The CXB1818Q is a high-speed monolithic Laser
Diode Driver/Current Switch with ECL/PECL input
level. Open collector outputs are provided at the
output pins (Q, QBX) and have the capacity of driving
modulation current of 50mAp-p at a maximum data
rate of 622Mbps. Along with the modulation current
generator there is the laser diode bias current
generator which has capacity of sourcing up to 60mA
(Bias). The laser diode bias current can be controlled
by either a voltage or current into the bias adjust pin
(BiasAdj) and the bias set pin (SBias), depending on
how these pins are configured. Control of the bias
current is achieved through the APC (Automatic
Power Control) circuit. In order to avoid having a
large current go through the laser diode, this IC also
provides an Activity detector function for laser
protection. The Activity detector circuit detects data
edge transitions and if no data transition occurs after
a certain period, then both the modulation and bias
currents are shutdown. The bias currents are shut it
down by in order to pull down the output voltage of
APC OP.Amp.
When the automatic shutdown is conducted, it is
possible to select whether the laser diode alarm
output is activated or not. Additionally, this IC has
the DFF for the input signal correction and the
internal Duty Cycle correction circuit that can control
the falling edge of the input pulse up to a maximum
of 1.0ns(Min.).
40 pin QFP (Plastic)
Applications
• SONET/SDH: 622Mbps
• Fibre channel: 531Mbps
Absolute Maximum Ratings
• Supply voltage VCC – VEE –0.3 to +6.0 V
• Input voltage VIN
VEE to VCC
V
• Differential input voltage
| VD – VDB |
0 to 2.5
V
• Bias output current
0 to 80 mA
• SBias input/output current
0 to 5
mA
• Bias control current
IBset (Ibiasadj) 0 to 5
mA
• Bbias control voltage
VBset (Vbiasadj) 0 to 3
V
• Modulation output current
70
mA
• Modulation adjust current
IQset (Idrvadj) 0 to 15 mA
• Storage temperature
Tstg
–65 to +150 °C
Features
• Maximum data rate (NRZ): 622Mbps
• Alarm and Shutdown function
• DFF for input signal correction
• Input signal Duty cycle correction
• Automatic Power Control (APC) for bias current
Recommended Operating Conditions
• DC supply voltage
VCC – VEE 3.14 to 3.46 V
• Operating ambient temperature
Ta
–40 to +85 °C
• Activity detector function for laser protection
• Alarm signal mask function during shutdown
• Differential PECL inputs or AC coupled inputs
Structure
Bipolar silicon monolithic IC
Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by
any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the
operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.
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E99227-PS