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) Rev. SpA | Page 2 of 2