EL6119

The EL6119 is a dual four-channel laser diode current amplifier that provides controlled current to both a CD and DVD laser diode. Channels 2, 3, and 4 should be used as the write channels, with switching speeds of approximately one nanosecond rise/fall time. All four channels are summed together at the I _OUT output, allowing the user to create multilevel waveforms in order to optimize laser diode performance. The level of the output current is set by an analog voltage applied to an external resistor which converts the voltage into a current at the I_IN  pin (virtually ground). The current seen at this pin is then amplified to become a current source at pin I _OUT.

Output current pulses are enabled when an 'L' signal is applied to the WEN pin. No output current flows when WEN is 'H' and additional laser diode protection is provided since
the WEN input will float high when open. Complete I _OUT shutoff is also achieved by holding the ENABLE pin low, which will override the WEN control pins.

Each laser driver EL6119 has a separate ENABLE pin to allow total shutdown of each laser driver when not in use.

An on-chip 500MHz oscillator EL6119 is provided to allow output current modulation when in read mode. The oscillator is enabled when the OSCEN pin is held high. Complete control of amplitude and frequency is set by two external resistors connected to ground at pins R_FREQ  and R_AMP  (see graphs in this data sheet for further explanation).