Analog Devices AD9664 SpA Datasheet

4-Channel LVDS Dual-Output
L

FEATURES

Dual-current controlled output current sources with 4 input
channels TTL selectable output Stable on-chip oscillators with independent frequency and
amplitude control TTL or LVDS selectable write channel enables Independent TTL oscillator enable 150 mA minimum output current for Read Channel 325 mA minimum output current for Write Channel 1 250 mA minimum output current for Write Channel 2 150 mA minimum output current for Write Channel 3 Rise time/fall time of 0.8 ns Low output overshoot Low power consumption Single 5 V power supply (±10%)

APPLICATIONS

DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM
supercombo drives MO drives Laser diode current switching

GENERAL DESCRIPTION

The AD9664 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 OSCEN pin is controlled by a TTL signal. All channels are summed at the selected LD output pin where Write Channel 1 can contrib­ute a minimum 325 mA maximum output current, and Write Channel 2 and Write Channel 3 can contribute a mini­mum of 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 xSET 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.
Laser Diode Driver with Oscillator
AD9664

FUNCTIONAL BLOCK DIAGRAM

W3SET
W3DIS
W3DISN
W2SET
W2DIS
W2DISN
W1SET
W1DIS
W1DISN
RSET
RDIS
OSCEN
FADJ1 FADJ2
Figure 1. 4-Channel LVDS Laser Driver Block Diagram
Figure 2. 4-Channel LVDS Laser Driver Pin Configuration
For more information about the AD9664, contact Analog Devices at high_current_drivers.com@analog.com.
WRITE
CHANNEL 3
WRITE
CHANNEL 2
WRITE
CHANNEL 1
READ CHANNEL
OSCILLATOR
1
W3DISN
W3DIS
2
GND
3
GND
4
W2DISN
5
W2DIS
6
W1DISN
7
W1DIS
8
AADJ2
AADJ1
HVDD
N/C30 OSCEN29 OUTSE
32
31
AD9664
LFCSP
5mm × 5mm
(Not to Scale)
9
11
10
RDIS
AVDD
AVDD
INS OUTSEL
FADJ127 FADJ226 AADJ125 AADJ2
28
14
W3SET12W2SET13W1SET
15
RSET
16
ENABLE
24 23 22 21 20 19 18 17
INS LVDD LD1 LD1 GND LD2 LD2 LVDD
OUTPUT A
OUTPUT B
ENABLE
04597-Sp0-002
LD1
LD2
04597-Sp0-001
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 © 2004 Analog Devices, Inc. All rights reserved.
AD9664
© 2004 Analog Devices, Inc. All rights reserved. Trademarks and regis­tered trademarks are the property of their respective owners.
D04597–0–4/04(SpA)
Rev. SpA | Page 2 of 2
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