ELANT EL6277CU Datasheet

EL6277C - Product Brief

3-Channel Laser Diode Driver + Oscillator

EL6277C - Product

Features

• Ultra-Small Package Outline

• High-performance laser diode

driver

• Current-controlled output current

source, 100 mA channel R and 2,
200mA channel 3, requiring one
external set resistor per channel

• Rise time = 3.0 ns

• Fall time = 3.5ns

• On chip oscillator with frequency

and amplitude control by use of
external res istors to ground

• Oscillator to 500 MH z

• 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

Application

• CD-RW applications

• Writable optical drives

• Laser diode current switching

Ordering Information

Part No Temp. Range Package Outline #

EL6277CU 0°C to +70°C QSOP-16 MDP0041

General Description

The EL6277C is a high-performance three channel laser diode current
driver that provides controlled current to a grounded laser diode.
Channel R and 2 can provide 100mA per channel of DC or pulsed cur­rent, while channel 3 can provide 200mA per channel. Channels 2, and
3 must be used as th e write c hannels, with switch ing speeds o f app rox­imately three 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 I
(near ground). The current seen at this pin is then amplified by 100X
to become a cu r rent source at pi n I

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 either of the
OUTEN pins for chan nels 2 or 3(th e write ch ann els) a re low (s ee trut h
table).

Output current pulses are enabled when a ‘Low’ 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 the OUTEN con­trol pins.

The external resistors allow the user to accurately and independently
set each ampli fier trans conductan ce by apply ing a volt age to each
resistor, without restriction on the vo ltage ra ng e. Alte rnat i vely , th e I
pin can be biased from a curr ent DAC or other current source.

output, allowing the u ser t o c re at e mu lti-

OUT

.

OUT

shut-off is also achieved by

OUT

pin

IN

IN

© 1997 Elantec, Inc.

Connection Diagram

I

INR

I

IN2

GND

RFREQ

I

IN3

OUTENR

OUTEN2
OUTEN3

1

2

3

4

5

6

7

8 9

16

15

14

13

12

11

10

V

CC

V

CC

I

OUT

GND
RAMP
ENABLE
OSCEN
V

CC

February 22, 2000

EL6277C - Product Brief

3-Channel Laser Diode Driver + Oscillator

EL6277C - Product

General Disclaimer

Specifications contained in this data sheet are in effect as of the publicat ion date shown. Elantec, Inc. re serves the r ight to make changes in th e cir­cuitry or specifications cont ained herein at a ny time without notice. Elantec , Inc. assumes no res ponsibili ty for t he us e of an y circuits descr ibed
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 intend ed to sup-

Elantec, Inc.

675 Trade Zone Blvd.
Milpitas, CA 95035
Telephone: [phone]

[phone] (toll free)
Fax: [phone]
European Office: 44-18-977-6020

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 applicatio n of Elantec, Inc. P roducts in Li fe 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 cov er injury to persons or prop erty or
other consequential damages.

February 22, 2000

2

Printed in U.S.A.