The EL6119 is a dual four-channellaser diode current amplifier thatprovides controlled current to both aCD and DVD laser diode. Channels 2, 3, and 4 should beused as the write channels, with switching speeds ofapproximately one nanosecond rise/fall time. All fourchannels are summed together at the IOUT output, allowingthe user to create multilevel waveforms in order to optimizelaser diode performance. The level of the output current isset by an analog voltage applied to an external resistorwhich converts the voltage into a current at the IIN pin(virtually ground). The current seen at this pin is thenamplified to become a current source at pin IOUT.Output current pulses are enabled when an ‘L’ signal isapplied to the WEN pin. No output current flows when WENis ‘H’ and additional laser diode protection is provided sincethe WEN input will float high when open. Complete IOUTshutoff is also achieved by holding the ENABLE pin low,which will override the WEN control pins.