The AD9662 is a laser diode driver for high performance CD and DVD recordable drives. It includes three channels for three different optical power levels: the read channel generates a continuous output power level, whereas Channel 2 and Channel 3 are used as write channels having 0.8 ns rise/fall times. All channel currents are summed at the IOUT pin. Each channel's output current is established by multiplying the channel's gain by the channel's input current. The input current for each of the input channels--INR, IN2, and IN3--can be set either by using an external resistor that converts an input voltage to a current or by directly using a current source.