AD9660 Datasheet, PDF (1/12 Pages) Analog Devices – 200 MHz Laser Diode Driver with Light Power Control

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FEATURES
1.5 ns Rise/2.0 ns Fall Times
Output Current: 180 mA @ 3 V, 200 mA @ 2.5 V
Bias Current: 90 mA @ 3 V
Modulation Current: 60 mA @ 3 V
Offset Current: 30 mA @ 3 V
Single +5 V Power Supply
Switching Rate: 200 MHz
Onboard Light Power Control Loops
APPLICATIONS
Laser Printers and Copiers
Optical Disk Drives
FO Datacomm
200 MHz Laser Diode Driver
with Light Power Control
AD9660
FUNCTIONAL BLOCK DIAGRAM
WRITE
PULSE
WRITE
CALIBRATE
WRITE
LEVEL
BIAS
LEVEL
BIAS
CAL
T/H
V:1
OUTPUT
DRIVER
TRANSIMPEDANCE
AMPLIFIER
BIAS
T/H
V:1
OUTPUT
DRIVER
AD9660
OUTPUT
SENSE
INPUT
PHOTO
DETECTOR
DIODE
LASER
DIODE
GENERAL DESCRIPTION
The AD9660 is a highly integrated driver for laser diode appli-
cations such as optical disk drives, printers, and copiers. The
AD9660 gets feedback from an external photo detector and in-
cludes two analog feedback loops to allow users to set “bias”
and “write” (for optical disk drives) power levels of the laser,
and switch between the two power levels at up to 200 MHz.
Output rise and fall times are typically 1.5 ns and 2.0 ns to
complement printer applications that use image enhancing tech-
niques such as pulse width modulation to achieve gray scale,
and allow disk drive applications to improve density and take
advantage of pulsed write formats. Control signals are TTL/
CMOS compatible.
The driver output provides up to 180 mA of current @ 3 V,
90 mA of BIAS current, 60 mA of modulation current, and
30 mA of offset current. The onboard disable circuit turns off
the output drivers and returns the light power control loops to a
safe state.
The AD9660 can also be used in closed loop applications in
which the output power level follows an analog WRITE LEVEL
voltage input. By optimizing the external hold capacitor, and
the photo detector, the write loop can achieve bandwidths as
high as 25 MHz.
The AD9660 is offered in a 28-pin plastic SOIC for operation
over the commercial temperature range (0°C to +70°C).
REV. 0
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use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
© Analog Devices, Inc., 1995
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