T0816

The T0816 is a laser diode driver for the operation of a grounded laser diode forCD-RW drives. It includes three channels for three different optical power levels whichare controlled by a separate IC. The read channel generates a continuous output levelwhereas channels 2 and 3 are provided as write channels with very fast switchingspeeds. Write current pulses are enabled when a 'low' signal is applied to the NE pins.

All channels are summed together at the IOUT pin. Each channel can contribute up to250 mA to the total output current of up to 300 mA. A total gain of 100 (read channel),250 (channel 2) and 150 (channel 3) are provided between each reference currentinput and the output. Although the reference inputs are current inputs voltage controlis possible by using external resistors.

An on-chip RF oscillator is provided to reduce laser mode hopping noise during readmode. Frequency and swing can be set by two external resistors. Oscillation isenabled by a 'high' at the ENOSC pin. Complete output current and oscillator switch-off is achieved by a 'low' at the ENABLE input.