T0816_05 Datasheet, PDF (1/15 Pages) ATMEL Corporation – 3-channel Laser Driver with RF Oscillator

Features
• Current-controlled Output Current Source, 3 Input Channels
• Low-power Consumption
• Output Current per Channel to 250 mA
• Total Output Current to 300 mA
• Rise Time 1.0 ns, Fall Time 1.1 ns
• On-chip RF Oscillator
• Control of Frequency and Swing by Use of 2 External Resistors
• Oscillator Frequency Range from 200 MHz to 500 MHz
• Oscillator Swing to 100 mA
• Single 5V Power Supply
• Common Enable, Disable Input
• TTL/CMOS Control Signals
• Small SSO16 Package and QFN16 Package
Applications
• CD-RW Drives
• Writable Optical Drives
3-channel Laser
Driver with RF
Oscillator
T0816
1. Description
The T0816 is a laser diode driver for the operation of a grounded laser diode for
CD-RW drives. 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 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 at the IOUT pin. Each channel can contribute up to
250 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 current
input and the 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. Frequency and swing can be set by two external resistors. Oscillation is
enabled by a ‘high’ at the ENOSC pin. Complete output current and oscillator switch-
off is achieved by a ‘low’ at the ENABLE input.
Rev. 4505H–DVD–11/05