EL6245C - Product Brief
EL6245C - Product Brief
3-Channel Laser Diode Driver w/Oscillator & APC Amplifier
Features
• “Shrink-Small” Outline Package
• Voltage-controlled output current
source, requiring one external set
resistor per channel
• Auto oscillator on-off with
OUTEN signals
• 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
• Fast Settling APC Amplifier
General Description
The EL6245C 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
OUT
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 I
IN
pin
(virtually 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 output current
modulation when in any mode. This is turned on only when the
OSCEN and OUTEN pins are held high. Complete control of ampli-
tude 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 addi-
tional laser diode protection is provided since the OUTEN input will
float high when open. Complete I
OUT
shut-off is also achieved by
holding the ENABLE pin low, which will override all other control
pins.
The EL6245C 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
Ordering Information
Part No.
EL6245CU
Temp. Range
0°C to +70°C
Package
16-Pin QSOP
Outline #
MDP0041
Connection Diagram
1 VOUT
2 VREF
3 IINR
4 IIN2
5 IIN3
6 RFREQ
7 OUTEN3
8 OUTEN2
PDIN 16
VCC 15
IOUT 14
GND 13
October 25, 2001
RAMP 12
ENABLE 11
OSCEN 10
VCC 9
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 ]
