EL6286C Datasheet, PDF (1/2 Pages) Elantec Semiconductor – 4-Ch Laser Diode Driver + Oscillator

EL6286C - Product Brief
4-Ch Laser Diode Driver + Oscillator
Features
• “Shrink-Small” Outline Package
• Voltage-controlled output current
source requiring one external set
resistor per channel
• Current-controlled output current
source
• 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
• Single +5V supply (±10%)
• Disable feature for power-up
protection and power savings
• CMOS control signals
Applications
• CD-RW applications
• Writable optical drives
• Laser diode current switching
Ordering Information
Part No
EL6286CU
Temp. Range
0°C to +70°C
Package
QSOP-24
Outline #
MDP0040
General Description
The EL6286C is a four channel laser diode current amplifier that pro-
vides controlled current to a grounded laser diode. Channels 2, 3, and
4 must be used as the write channels, with switching speeds of approx-
imately one 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 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_IN pin (virtu-
ally ground). The current seen at this pin is then amplified 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.
Connection Diagram
GND 1
IINR 2
GND 3
IIN2 4
RFREQ 5
IIN3 6
IIN4 7
OUTENR 8
OUTEN2 9
OUTEN3 10
OUTEN4 11
GND 12
24 GND
23 VCC
22 VCC
21 IOUT
20 IOUT
19 GND
18 RAMP
17 ENABLE
16 OSCEN
15 VCC
14 VCC
13 GND
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.