The SL5028 is a dual three-channel laser driver that provides controlled current to two grounded laser diodes.

The SEL1 pin selects LD1 or LD2 pin active to drive either CD or DVD laser diode.

The currents flowing into IR, I2 and I3 determine the level of the output current with gains 100 for all channels.

The channel enable pins NE2 and NE3 determine current waveform timing. The output write current pulses are enabled when a low is applied to NEx pins with switching speed less than 1 ns rise/fall time.

Two on-chip oscillators can provide up to 500MHz modulation to the output current. Pin OSEN is held high to turn on the oscillators. Each oscillator’s amplitude is set by an external resistor connected to ground from RA1 or RA2. And frequency is set from RF.

The total output current is the sum of current from the four charnels and the oscillator. LD1or LD2 is enabled when SEL1 is high or low respectively.

There is a whole chip enable pin ENA needed to be high. And complete LD shut-off is achieved by holding ENA low.