The AD9664 is a laser diode driver for high performance CD-RW and DVD recordable drives. It includes four channels for four different optical power levels: the Read Channel generates a continuous output power level, whereas Channel 1, Channel 2, and Channel 3 can be used as write channels that can be controlled with an LVDS or TTL interface. The OSCEN pin is controlled by a TTL signal. All channels are summed at the selected LD output pin where Write Channel 1 can contribute a minimum 325 mA maximum output current, and Write Channel 2 and Write Channel 3 can contribute a minimum of 250 mA and 150 mA, respectively. The level of the output current is set by an external resistor, which converts this voltage into a current at the xSET pin.