ELANT EL6276CU Datasheet

EL6276C - Product Brief
4-Ch Laser Diode Driver + Oscillator
EL6276C - Product Brief
Features
• “Shrink-Small” Outline Package
• Voltage-controlled output current source to 140mA per channel, requiring one external set resistor per channel
• Current-controlled output current source to 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 = 100X
• Disable feature for power-up protection and power savings
• TTL/CMOS control signals
Applications
• CD-RW applications
• Writable optical drives
• Laser diode current switching
Ordering Information
Part No Temp. Range Package Outline #
EL6276CU 0°C to +70°C QSOP-24 MDP0040
General Description
The EL6276C is a four channel laser diode current amplifier that pro­vides controlled current to a grounded laser diode. The four amplifiers can provide up to 140mA per channel of DC or pulsed current. Chan­nels 2, 3, and 4 must be used as the write channels, with switching speeds of approximately three nanosecond rise/fall time. All four channels are summed together at the I
output, allowing the user to
OUT
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 I
OUT
.
An on-chip 500MHz oscillator is provided to allow 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 I
shutoff is also achieved by hold-
OUT
ing the ENABLE pin low, which will override all other 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
1 2 3 4 5 6 7 8
9 10 11 12
IINR GND IIN2 RFREQ IIN3 IIN4 OUTENR OUTEN2 OUTEN3 OUTEN4 GND
GNDGND
VCC
VCC IOUT IOUT
GND
RAMP
ENABLE
OSCEN
VCC
VCC
GND
24 23 22 21 20 19 18 17 16 15 14 13
September 28, 2000
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.
EL6276C - Product Brief
4-Ch Laser Diode Driver + Oscillator
EL6276C - Product Brief
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 sup-
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
port 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.
September 28, 2000
2
Printed in U.S.A.
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