Dual, current-controlled output current sources with 4 input
Stable on-chip oscillators with independent frequency and
TTL- or LVDS-selectable write channel enables negative logic
Independent TTL oscillator enables positive logic
170 mA minimum output current for the read channel
510 mA minimum output current for Write Channel 1
330 mA minimum output current for Write Channel 2
165 mA minimum output current for Write Channel 3
950 mA typical total output current
Typical rise time/fall time of 0.8 ns
Low power consumption
Single 5 V power supply (±10%)
DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM
Magneto-optical (MO) drives
Laser diode current switching
The AD9665 is a laser diode driver for high performance CD-
RW and DVD recordable drives. It includes four channels for
four different optical power levels: the read channel generates a
continuous output power level, whereas Channel 1, Channel 2,
and Channel 3 can be used as write channels that can be
controlled with an LVDS or TTL interface. The WxDIS and
RDIS pins are active low logic. The OSCEN pin is controlled by
an active high TTL signal. All active channels are summed at
the output where Write Channel 1 can contribute at least 325
mA output current, and Write Channel 2 and Write Channel 3
can contribute at least 250 mA and 150 mA, respectively. The
level of the output current is set by an external resistor, which
converts this voltage into a current at the WxSET pin.
An on-chip oscillator is provided to allow output current
modulation and to reduce laser-mode hopping. Four external
resistors permit the setting of two distinct values for the
frequency and swing of the oscillator. The oscillator can output
up to 100 mA p-p of current (push-pull oscillator) with a
frequency range of 200 MHz to 500 MHz.
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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.
Laser Diode Driver with Oscillator
4-Channel, LVDS, Dual-Output,
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
For more information on the AD9665, email Analog Devices, Inc.
Figure 2. 4-Channel, LVDS, Laser Driver Pin Configuration
Figure 1. 4-Channel, LVDS, Laser Driver Block Diagram
FUNCTIONAL BLOCK DIAGRAM
*TTL ACTIVE LOW SEE TABLE 3
© 2005 Analog Devices, Inc. All rights reserved.
(Not to Scale)