6

Typical Application Circuit

Applications Information

Product Description

The EL6202 is a solid state, low-power, high-speed laser

modulation oscillator with external resistor-adjustable

operating frequency. It is designed to interface easily to laser

diodes to break up optical feedback resonant modes and

thereby reduce laser noise. The output of the EL6202 is

composed of a push current source switched at the oscillator

frequency. The output and oscillator are automatically

disabled for power saving when the average input current

drops to less than 100µA. The EL6202 has the operating

frequency from 60MHz to 600MHz and the output current

30mA (includes laser current) for the output current of

1

2

3

5

4

VDD1

RFREQ

GND

IOUT

IIN

CONTROLLER

LOOP

COMPENSATION-

NOISE

REDUCTION

CAPACITOR

FREQUENCY

SETTING

RESISTOR

EMI

REDUCTION

SUPPLY

FILTER

GAIN

SETTING

RESISTOR

TYPICAL

ROM LASER

DRIVER

LASER DIODE

PHOTO DIODE

BEAD

+5V

FLEX

GND

0.1µF

4.7µF

EMI

BLOCKING

RESISTOR

Either the high current controller resistor can be

reduced to 2mA full scale, or the transistor and resistor

can be replaced with a resistor from the controller DAC.

DAC

LASER OUTPUT

POWER

LASER CURRENT

0mW

~10mW

0mA

~60mA

OSCILLATOR CURRENT

LASER OUTPUT POWER

THRESHOLD

CURRENT

optional

EL6202