The EL6208 is a dual push-pull
oscillator used to reduce laser noise in
twin laser diodes. It uses the standard
interface to existing ROM controllers. The frequency and
amplitude are both 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 activates the oscillator only when
the APC current is applied.
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 utility
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. The waveform is
filtered to reduce EMI emissions.