4-Channel, LVDS, Dual-Output, Laser Diode Driver with Oscillator Data Sheet AD9665 FEATURES FUNCTIONAL BLOCK DIAGRAM W3SET Dual, current-controlled output current sources with 4 input WRITE W3DIS CHANNEL 3 channels W3DISN TTL-selectable output Stable on-chip oscillators with independent frequency and W2SET WRITE OUTPUT A LD1 W2DIS CHANNEL 2 amplitude control W2DISN TTL- or LVDS-selectable write channel enables negative logic Independent TTL oscillator enables positive logic W1SET WRITE W1DIS CHANNEL 1 170 mA minimum output current for the read channel W1DISN 510 mA minimum output current for Write Channel 1 OUTPUT B LD2 330 mA minimum output current for Write Channel 2 RSET READ CHANNEL 165 mA minimum output current for Write Channel 3 RDIS 950 mA typical total output current Typical rise time/fall time of 0.8 ns OSCEN OSCILLATOR ENABLE Low power consumption Single 5 V power supply (10%) INS OUTSEL F F A A ADJ1 ADJ2 ADJ1 ADJ2 APPLICATIONS Figure 1. 4-Channel, LVDS, Laser Driver Block Diagram DVD-R, DVD+R, DVD-RW, DVD+RW, DVD-RAM supercombo drives Magneto-optical (MO) drives Laser diode current switching OTDR laser drivers 1 24 W3DISN INS GENERAL DESCRIPTION W3DIS* 2 23 V DD 3 GND 22 LD1 The AD9665 is a laser diode driver for high performance CD-RW AD9665 4 21 GND LD1 LFCSP and DVD recordable drives. It includes four channels for four 5mm 5mm W2DISN 5 20 GND (Not to Scale) 6 19 different optical power levels: the read channel generates a W2DIS* LD2 7 18 LD2 W1DISN continuous output power level, whereas Channel 1, Channel 2, W1DIS* 8 17 V DD 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 *TTL ACTIVE LOW the output where Write Channel 1 can contribute at least 325 mA output current, and Write Channel 2 and Write NOTES 1. DNC = DO NOT CONNECT. LEAVE THIS PIN Channel 3 can contribute at least 250 mA and 150 mA, FLOATING WITH NO EXTERNAL CONNECTION. 2. WHEN PULLING A HIGH CURRENT, ATTACH respectively. The level of the output current is set by an HEAT SINK ON THE EXPOSED PAD. external resistor, which converts this voltage into a current Figure 2. 4-Channel, LVDS, Laser Driver Pin Configuration, See Table 3 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. Rev. F Document Feedback 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. 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Technical Support www.analog.com 9 32 V RDIS DD 10 31 DNC V DD OSCEN 11 30 V DD 29 OUTSEL W3SET 12 F 13 28 W2SET ADJ1 27 F W1SET 14 ADJ2 26 A RSET 15 ADJ1 A 16 25 ENABLE ADJ2 05269-050 05269-001AD9665 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Board Layout ..................................................................................9 Applications ....................................................................................... 1 Temperature Considerations .......................................................9 General Description ......................................................................... 1 Shutdown Supply Current Variation ....................................... 11 Functional Block Diagram .............................................................. 1 Evaluation Board ............................................................................ 12 Revision History ............................................................................... 2 Schematic..................................................................................... 12 Specif icat ions ..................................................................................... 3 O p erat ion ......................................................................................... 13 Absolute Maximum Ratings ............................................................ 5 Pin Descriptions ......................................................................... 13 ESD Caution .................................................................................. 5 Outline Dimensions ....................................................................... 14 Typical Performance Characteristics ............................................. 6 Ordering Guide .......................................................................... 14 Logic Table ......................................................................................... 8 Applications Information ................................................................ 9 REVISION HISTORY 9/15Rev. E to Rev. F Changed N/C Pin to DNC Pin .................................... Throughout Changes to Applications Section and Figure 2 ............................. 1 Changes to Figure 3 to Figure 6 and Figure 8 ............................... 6 Change to Figure 12 ......................................................................... 7 Change to Table 5 ........................................................................... 13 8/10Revision E: Initial Version Rev. F Page 2 of 16