ELANT EL6248CU Datasheet

EL6248C - Product Brief

3-Channel Laser Diode Driver w/Oscillator & APC Amplifier

EL6248C - Product Brief

Features

• “Shrink-Small” Outline Package

• Voltage-controlled output current
source requiring one external set
resistor per channel

• Current-controlled output current
source

• CH2 to 250mA max

• CH3 to 150mA max

• Rise time = 0.8ns

• Fall time = 0.8ns

• On chip oscillator with frequency
and amplitude control by use of
external resistors to ground

• Oscillator to 500MHz

• Oscillator to 100mA pk/pk

• Auto-oscillator for read

• Single +5V supply (±10%)

• Disable feature for power-up
protection and power savings

• Fast Settling APC Amplifier

Applications

• CD-RW applications

• Writable optical drives

• Laser diode current switching

General Description

The EL6248C is a high-performance three channel laser driver that
provides controlled current to a grounded laser diode. Channels 2 and
3 should be used as the write channels, with switching speeds of
approximately one nanosecond rise/fall time. All three channels are
summed together at the I
level 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 to
become a current source at pin I

An on-chip 500MHz oscillator is provided to allow output current
modulation when in any mode. This is turned on when the OSCEN
and OUTEN pins are 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
holding the ENABLE pin low, which will override all other control
pins.

The EL6248C also includes a fast settling APC amplifier designed to
interface directly with the front end monitor diode and the sample­and-hold amplifier for read and write power control. Its 100MHz
bandwidth and 30ns settling time enable up to 16X CD-RW design.

output, allowing the user to create multi-

OUT

.

OUT

shut-off is also achieved by

OUT

Ordering Information

Part No Temp. Range Package Outline #

EL6248CU 0°C to +70°C 24-Pin QSOP MDP0040

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.

Connection Diagram

1

VOUT PDIN

2

VREF VCC

3

IINR VCC

4

IIN2 IOUT

5

RFREQ IOUT

6

IIN3 GND

7

OUTENR RAMP

8

OUTEN3 ENABLE

9

OUTEN2 OSCEN

10

GND VCC

11

NC GND

12

NC NC

24
23
22
21
20
19
18
17
16
15
14
13

October 25, 2001

EL6248C - Product Brief

3-Channel Laser Diode Driver w/Oscillator & APC Amplifier

EL6248C - 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: [phone]

(888) ELANTEC
Fax: [phone]
European Office: [phone]
Japan Technical Center: [phone]

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.

October 25, 2001

2

Printed in U.S.A.