atr0841

Manufacturer Part Numberatr0841
Description4-channel Laser Driver With 2 Outputs, 3 Lvds Inputs And Internal Termination - Atmel Corporation
ManufacturerATMEL Corporation
atr0841 datasheet
 
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Features
Current-controlled Output Current Source with 4 Input Channels
LVDS Compatible Inputs, Channel 2, 3, and 4, with On-chip 100 Ω Termination
Two Selectable Outputs for Grounded Laser Diodes
Output Current per Channel up to 350 mA
Total Output Current up to 500 mA
On-chip RF Oscillator
Control of 2 Different Swings and Frequencies by Use of 4 External Resistors
Oscillator Frequency Range from 200 MHz to 500 MHz
Maximum Oscillator Current Amplitude 100 mApp
Single 5 V Power Supply
Small Pb-free QFN24 4 mm × 4 mm Package
Applications
DVD Blue Laser
DVD-RAM/DVD-RW/DVD+RW with CD-RW Capability
Recordable Optical Drives
Description
The ATR0841 is a laser diode driver designed to operate two differently grounded
laser diodes for DVD-RW/+RW (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 by fast LVDS (Low Voltage Differential Signaling). Due to the inte-
grated termination external resistors are not needed.
The function of the read channel is to generate a continuous output current, channels
2 to 4 are designed as write channels with very fast switching speed. All channels are
summed together and routed to one of the two outputs, IOUTA or IOUTB, controlled
by the select input SELA. Each write channel (channels 2 to 4) can contribute up to
350 mA to the total output current of up to 500 mA. The read channel can contribute
up to 150 mA. Total gain of 100 (read channel) and 250 (channel 2, 3 and 4), respec-
tively, 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 available to reduce laser-mode hopping
noise during read mode. The oscillator current amplitude can be set independently for
the two selectable outputs with two different resistors. Oscillation is enabled by a high
signal at the ENOSC pin. Complete shut down of the output currents is achieved by a
low signal at the ENABLE input.
In case of uncertain (balanced) enable signals, a built-in protection circuit keeps the
laser diode output current within the defined range.
4-channel Laser
Driver with
2 Outputs,
3 LVDS Inputs
and Internal
Termination
ATR0841
Summary
Rev. 4818AS–DVD–09/04

atr0841 Summary of contents

  • Page 1

    ... Recordable Optical Drives Description The ATR0841 is a laser diode driver designed to operate two differently grounded laser diodes for DVD-RW/+RW (650 nm) and CD-RW (780 nm). The device includes four channels for four different optical power levels. The write channels (channel can be controlled by fast LVDS (Low Voltage Differential Signaling). Due to the inte- grated termination external resistors are not needed ...

  • Page 2

    ... ATR0841 2 Figure 1. Block Diagram I4 E4 NE4 I3 E3 NE3 I2 E2 NE2 IR ENABLE ENOSC RFA RFB RSA RSB Channel 4 Channel 3 IOUTA IOUTB Channel 2 Channel 1 Read Channel RF oscillator SELA 4818AS–DVD–09/04 ...

  • Page 3

    Pin Configuration Figure 2. Pinning QFN24 Pin Description Pin Symbol Type 1 RFB Analog 2 RFA Analog 3 E2 Digital 4 NE2 Digital 5 E3 Digital 6 NE3 Digital 7 E4 Digital 8 NE4 Digital 9 ENOSC Digital 10 ENABLE ...

  • Page 4

    ... Parameters Junction ambient, QFN24 Note: 1. Measured with multi-layer test board (JDEC standard) Recommended Operating Range Parameters Supply voltage Input current External resistor to GND to set oscillator frequency External resistor to GND to set oscillator swing Operating temperature range ATR0841 4 Symbol Value V -0 0.5 in ...

  • Page 5

    ... Ordering Information Extended Type Number ATR0841-PFQG Package Information 4818AS–DVD–09/04 Package Remarks Lead free QFN24 × Taped and reeled 5 ...

  • Page 6

    ... Fax: (81) 3-3523-7581 Disclaimer: Atmel Corporation makes no warranty for the use of its products, other than those expressly contained in the Company’s standard warranty which is detailed in Atmel’s Terms and Conditions located on the Company’s web site. The Company assumes no responsibility for any errors which may appear in this document, reserves the right to change devices or specifications detailed herein at any time without notice, and does not make any commitment to update the information contained herein ...