ATR0808 Datasheet | Atmel

Features - - - - - - - - - - - - - Current-controlled Output Current Source with 3 Input Channels Two Selectable Outputs for Grounded Laser Diodes Output Current per Write Channel: 350 m A Total Output Current: 500 m A 200 Ω Channel Input Resistance On-chip RF Oscillator Control of Two Different Swings by Use of Two External Resistors Oscillator Frequency Range from 200 MHz to 500 MHz Oscillator Swing: 100 m A Single 5 V Power Supply mon Enable/Disable Input TTL/CMOS Control Signals Small Pb-free QFN16 (4 mm × 4 mm) or SSO16 Package Applications - - - - DVD-ROM with CD-RW Capability DVD+RW with CD-RW Capability DVD-RW with CD-RW Capability Writable Optical Drives Three Channel Laser Driver with RF Oscillator and Two Outputs ATR0808 Summary Description The ATR0808 is a laser diode driver for the operation of two different grounded laser diodes for DVD-RW/DVD+RW (650 nm) and CD-RW (780 nm). It includes three channels for three different optical power levels which are controlled by a separate IC. The read channel generates a continuous output level, whereas the channels 2 and 3 are provided as write channels with very fast switching speeds. Write current pulses are enabled when a low signal is applied to the NE pins. All channels are summed together and switched to one of the two IOUTA or IOUTB outputs by the select input SELA. Each write channel (channel 2 and 3) can contribute up to 350 m A to the total output current, up to 500 m A. The read channel can contribute up to 150 m A. Total gains of 100 (read channel), 250 (channel 2 and 3) are provided between each reference current input and the selected output. Although, the reference inputs are current inputs, voltage control is possible by using external resistors. An on-chip RF oscillator is provided to reduce laser mode hopping noise during read mode. Swing can be set independently for the two selectable outputs with two different resistors. Oscillation is enabled by a high signal at the ENOSC pin. plete output...