EL6242C - Product Brief
3-Channel Laser Diode Driver w/Oscillator & APC Amplifier
Features
General Description
• Shrink-Small Outline Package
The EL6242C is a high-performance three channel laser driver that
provides controlled current to a grounded laser diode. Write 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 IOUT output, allowing the user to create multi-
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
• Voltage-controlled output current
source requiring one external set
resistor per channel
• Rise time = 0.8ns
• Fall time = 0.8ns
• On chip oscillator with frequency
and amplitude control by use of
external resistors to ground
become a current source at pin IOUT
.
• Oscillator to 500MHz
• Oscillator to 100mA pk/pk
• Single +5V supply (±10%)
• Disable feature for power-up
protection and power savings
An on-chip 500MHz oscillator is provided to allow output 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).
• Fast Settling APC Amplifier
The EL6242C also includes a fast settling APC amplifier designed to
interface directly with the front end monitor diode and the sample-
and-hold amplifier for read and write power control. Its 100MHz
bandwidth and 30ns settling time enable up to 16X CD-RW design.
Applications
• CD-RW applications
• Writable optical drives
• Laser diode current switching
Connection Diagrams
Ordering Information
1
2
3
4
5
6
7
8
9
VOUT
VREF
GND
IINR
PDIN 24
VCC 23
Part No.
EL6242CU
EL6242CL
Temp. Range
0°C to +70°C
0°C to +70°C
Package
QSOP-24
LPP-24
Outline #
MDP0040
MDP0046
VCC 22
IINR
IIN2
1
2
3
4
5
6
7
19 VCC
IOUT 21
IOUT 20
GND 19
18 IOUT
17 IOUT
16 GND
15 GND
14 RAMP
13 ENABLE
IIN2
IIN3
IIN3
RFREQ
GND
Thermal Pad
RFREQ
GND
GND
GND 18
RAMP 17
ENABLE 16
OSCEN 15
VCC 14
GND
10 WEN3
11 WEN2
12 GND
WEN3
GND 13
24-Pin QSOP
24-Pin LPP Top View
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 ]
