4-Channel Laser Diode Driver + Oscillator
General Description
• Shrink-small package outline
• Voltage-controlled output current
source to 150 mA per channel,
requiring one external set resistor
per channel
• Current-controlled output current
source to 150 mA per channel
• Rise time = 1.0 ns
• Fall time = 1.1 ns
• On chip oscillator with frequency
and amplitude control by use of
external resistors to ground
• Oscillator to 500 MHz
• Oscillator to 100 mA pk/pk
• Single +5V supply (±10%)
• Current amplification = 100
• Disable feature for power-up
protection and power savings
• TTL/CMOS control signals
The EL6255C is a high-performance four channel laser diode current
amplifier that provides controlled current to a grounded laser diode.
The four amplifiers can provide up to 150 mA per channel of DC or
pulsed current. Channels 2, 3, and 4 must be used as the write channels, with switching speeds of one nanosecond rise/fall time. All four
channels are summed together at the IOUT output, allowing the user to
create multilevel waveforms in order to optimize laser diode performance. The level of the output current is set by an analog voltage
applied to an external resistor which converts the voltage into a current
at the IIN pin (virtually ground). The current seen at this pin is then
amplified by 100X to become a current source at pin IOUT.
Output current pulses are enabled when an ‘L’ signal is applied to the
OUTEN pins. No output current flows when OUTEN is ‘H’, and additional laser diode protection is provided since the OUTEN input will
float high when open. Complete IOUT shut-off is also achieved by
holding the ENABLE pin low, which will override the OUTEN control pins.
DVD drives
CD-RW applications
Writable optical drives
Laser diode current switching
EL6255C - Product Brief
EL6255C - Product Brief
An on-chip 500 MHz oscillator is provided to allow current modulation when in the read mode. This is turned on when the OSCEN pin is
held high (floating not recommended). Complete control of amplitude
and frequency is set by two external resistors connected to ground at
pins RFREQ and RAMP (see graphs in this data sheet for further
explanation). The oscillator will also turn off whenever any of the
OUTEN pins for channels 2, 3, and 4 (the write channels) are low (see
truth table).
Connection Diagram
Ordering Information
Part No
Temp. Range
Outline #
0°C to +70°C
16 VCC
IIN2 2
15 VCC
IIN3 4
13 GND
Note: All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a “controlled document”. Current revisions, if any, to these
specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation.
© 2001 Elantec Semiconductor, Inc.
July 30, 1999
EL6255C - Product Brief
EL6255C - Product Brief
4-Channel Laser Diode Driver + Oscillator
General Disclaimer
Specifications contained in this data sheet are in effect as of the publication date shown. Elantec, Inc. reserves the right to make changes in the circuitry or specifications contained herein at any time without notice. Elantec, Inc. assumes no responsibility for the use of any circuits described
herein and makes no representations that they are free from patent infringement.
WARNING - Life Support Policy
Elantec, Inc. products are not authorized for and should not be used
within Life Support Systems without the specific written consent of
Elantec, Inc. Life Support systems are equipment intended to support or sustain life and whose failure to perform when properly used
in accordance with instructions provided can be reasonably
expected to result in significant personal injury or death. Users contemplating application of Elantec, Inc. Products in Life Support
Systems are requested to contact Elantec, Inc. factory headquarters
to establish suitable terms & conditions for these applications. Elantec, Inc.’s warranty is limited to replacement of defective
components and does not cover injury to persons or property or
other consequential damages.
July 30, 1999
Elantec Semiconductor, Inc.
675 Trade Zone Blvd.
Milpitas, CA 95035
Telephone: (408) 945-1323
(408) 945-9305
European Office: +44-118-977-6020
Japan Technical Center: +81-45-682-5820
Printed in U.S.A.