AD AD9662

3-Channel Laser Diode Driver
with Oscillator
AD9662
FEATURES
Current controlled current source
with 3 input channels
Output current for Channel 3—315 mA
Output current for other channels—210 mA
Rise time/fall time of 0.8 ns
On-chip oscillator
Single 5 V power supply (±10%)
Low output overshoot
Low power consumption
APPLICATIONS
FUNCTIONAL BLOCK DIAGRAM
IN3
OUTEN3
CHANNEL 3
IN2
OUTEN2
CHANNEL 2
IOUT
OUTPUT
INR
OUTENR
ENABLE
READ CHANNEL
CD-RW drives
DVD-RW, DVD+RW, MO drives
Laser diode current switching
OSCILLATOR
RF
The AD9662 is a laser diode driver for high performance CD
and DVD recordable drives. It includes three channels for three
different optical power levels: the read channel generates a
continuous output power level, whereas Channel 2 and
Channel 3 are used as write channels having 0.8 ns rise/fall
times. All channel currents are summed at the IOUT pin. Each
channel’s output current is established by multiplying the
channel’s gain by the channel’s input current. The input current
for each of the input channels—INR, IN2, and IN3—can be set
either by using an external resistor that converts an input
voltage to a current or by directly using a current source.
An on-chip oscillator is provided to allow output current
modulation (to reduce laser mode hopping). Two external
resistors control the frequency and the amplitude swing of the
oscillator. The push-pull oscillator can swing up to 100 mA p-p
and has a frequency range of 200 MHz to 500 MHz.
RS
Figure 1. AD9662 3-Channel Laser Diode Driver
INR 1
16 VCC
IN2 2
15 VCC
GND 3
14 IOUT
RF 4
IN3 5
AD9662
13 GND
12 RS
OUTENR 6
11 ENABLE
OUTEN2 7
10 OSCEN
OUTEN3 8
9
VCC
04389-0-002
GENERAL DESCRIPTION
04389-0-001
OSCEN
Figure 2. QSOP-16 Pinout
For more information about the AD9662, contact Analog Devices,
Inc. via email at: [email protected]
Rev. SpA
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.326.8703
© 2003 Analog Devices, Inc. All rights reserved.
AD9662
© 2003 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
C04389-0-12/03(SpA)
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