The EL6203 is a push-pull oscillator used to reduce laser
noise. It uses the standard interface to existing ROM
controllers. The frequency and amplitude are each set with a
separate resistor connected to ground. The tiny package
and harmonic reduction allow the part to be placed close to a
laser with low RF emissions. An auto turn-off feature allows
it to easily be used on combo CD-RW plus DVD-ROM
pick-ups.
One external resistor sets the oscillator frequency. Another
external resistor sets the oscillator amplitude. If the APC
current is reduced such that the average laser voltage drops
to less than 1.1V, the output and oscillator are disabled,
reducing power consumption to a minimum.
The current drawn by the oscillator consists of a small bias
current, plus the peak output amplitude in the positive cycle.
In the negative cycle, the oscillator subtracts peak output
amplitude from the laser APC current.
This part is pin-compatible to the EL6201. It is superior to the
EL6201 in several ways: It has up to 100mA output
capability, it is more power-efficient, it has less harmonic
content, and it has an auto shut-off feature activated at 1.1V.
The part is available in the space-saving 5 Ld SOT-23
package. It is specified for operation from 0°C to +70°C.