EL6276C - Product Brief
EL6276C - Product Brief
4-Ch Laser Diode Driver + Oscillator
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
General Description
The EL6276C is a four channel laser diode current amplifier that pro-
vides controlled current to a grounded laser diode. The four amplifiers
can provide up to 140mA per channel of DC or pulsed current. Chan-
nels 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
OUT
output, allowing the user to
create multilevel waveforms in order to optimize laser diode perfor-
mance. 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
IN
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 modula-
tion 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 exter-
nal 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 addi-
tional laser diode protection is provided since the OUTEN input will
float high when open. Complete I
OUT
shutoff is also achieved by hold-
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 I
IN
pin can be biased
from a current DAC or other current source.
Applications
• CD-RW applications
• Writable optical drives
• Laser diode current switching
Ordering Information
Part No
EL6276CU
Temp. Range
0°C to +70°C
Package
QSOP-24
Outline #
MDP0040
Connection Diagram
1 GND
2 IINR
3 GND
4 IIN2
5 RFREQ
6 IIN3
7 IIN4
GND 24
VCC 23
VCC 22
IOUT 21
IOUT 20
September 28, 2000
GND 19
RAMP 18
8 OUTENR ENABLE 17
9 OUTEN2
10 OUTEN3
11 OUTEN4
12 GND
OSCEN 16
VCC 15
VCC 14
GND 13
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.
ELANTEC [ ELANTEC SEMICONDUCTOR ]
