The ATR0842 is a laser diode driver designed to operate two differently grounded laser diodes. The output, IOUTA, can be used for a blue laser diode (400 nm) with up to 6V voltage drop by applying 8V at pin VCCH. The other output, IOUTB, supports legacy laser diodes for DVD-RW/+RW/RAM (650 nm) and CD-RW (780 nm). The device includes four channels for four different optical power levels. The write channels (channel 2 to 4) can be controlled either by fast LVDS (Low Voltage Differential Signaling) or by single-ended standard CMOS logic. In case of single-ended use, each of the enable inputs (NEx or Ex) can be used, the complementary input may be left open. There is no need for blocking or connection to a reference voltage.