ELANTEC EL6274CU

4-Ch Laser Diode Driver + Oscillator
Features
General Description
• Shrink Small Outline Package
• Voltage-controlled output current
source of 140mA per channel,
requiring one external set resistor
per channel
• Current-controlled output current
source of 140mA per channel
• Rise time = 3.0ns
• Fall time = 3.5ns
• On chip oscillator with frequency
and amplitude control by use of
external resistors to ground
• Oscillator to 500MHz
• Oscillator to 100mA pk/pk
• Single +5V supply (±10%)
• Current amplification = 100
• Disable feature for power-up
protection and power savings
• TTL/CMOS control signals
The EL6274C is a four channel laser diode current amplifier that provides controlled current to a grounded laser diode. The four amplifiers
can provide 140mA per channel of DC or pulsed current. Channels 2,
3, and 4 should be used as the write channels, with switching speeds of
approximately three 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.
Applications
• CD-RW applications
• Writable optical drives
• Laser diode current switching
Ordering Information
Part No
Temp. Range
Package
Outline #
EL6274CU
0°C to +70°C
QSOP-24
MDP0040
An on-chip 500MHz oscillator is provided to allow output current
modulation when in any mode. This is turned on when the OSCEN pin
is held high. 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).
Output current pulses are enabled when an ‘L’ signal is applied to the
OUTEN pin. 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 shutoff is also achieved by holding the ENABLE pin low, which will override OUTEN control pins.
The external resistors allow the user to accurately and independently
set each amplifier transconductance by applying a voltage to each
resistor, without restriction on the voltage range, thus ensuring broad
voltage DAC compatibility. Alternatively, the IIN pin can be biased
from a current DAC or other current source.
Connection Diagram
GND 1
24 GND
IINR 2
23 VCC
GND 3
22 VCC
IIN2 4
21 IOUT
RFREQ 5
20 IOUT
IIN3 6
19 GND
IIN4 7
18 RAMP
17 ENABLE
OUTEN2 9
16 OSCEN
OUTEN3 10
15 VCC
OUTEN4 11
14 VCC
GND 12
13 GND
May 2, 2001
OUTENR 8
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.
EL6274C - Product Brief
EL6274C - Product Brief
EL6274C - Product Brief
EL6274C - Product Brief
4-Ch 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.
May 2, 2001
Elantec Semiconductor, Inc.
675 Trade Zone Blvd.
Milpitas, CA 95035
Telephone: (408) 945-1323
(888) ELANTEC
Fax:
(408) 945-9305
European Office: +44-118-977-6020
Japan Technical Center: +81-45-682-5820
2
Printed in U.S.A.