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ATR0840 Dataheets PDF



Part Number ATR0840
Manufacturers ATMEL
Logo ATMEL
Description 4-channel Laser Driver
Datasheet ATR0840 DatasheetATR0840 Datasheet (PDF)

Features • • • • • • • • • • • Current-controlled Output Current Source with 4 Input Channels LVDS/CMOS Compatible Inputs Channel 2, 3, and 4 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 Q.

  ATR0840   ATR0840


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Features • • • • • • • • • • • Current-controlled Output Current Source with 4 Input Channels LVDS/CMOS Compatible Inputs Channel 2, 3, and 4 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 Package (4 mm × 4 mm) www.DataSheet4U.com Applications • DVD-RAM/DVD-RW/DVD+RW with CD-RW Capability • Recordable Optical Drives 4 Channel Laser Driver with 2 Outputs and 3 LVDS Inputs ATR0840 Summary Description The ATR0840 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 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. 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), respectively, 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. Rev. 4815AS–DVD–09/04 Figure 1. Block Diagram I4 E4 NE4 Channel 4 www.DataSheet4U.com I3 E3 NE3 Channel 3 IOUTA I2 E2 NE2 IOUTB Channel 2 IR Channel 1 Read channel ENABLE RF oscillator ENOSC RFA RFB RSA RSB SELA 2 ATR0840 4815AS–DVD–09/04 ATR0840 Pin Configuration Figure 2. Pinning QFN24 I4 I3 I2 IR VCC VCC www.DataSheet4U.com RFB RFA E2 NE2 E3 NE3 1 2 3 4 5 6 24 23 22 21 20 19 18 IOUTA 17 GND 16 RSA 15 RSB 14 IOUTB 7 8 13 SELA 9 10 11 12 Pin Description Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Paddle Symbol RFB RFA E2 NE2 E3 NE3 E4 NE4 ENOSC ENABLE VCC VCC SELA IOUTB RSB RSA GND IOUTA VCC VCC IR I2 I3 I4 GND Type Analog Analog Digital Digital Digital Digital Digital Digital Digital Digital Supply Supply Digital Analog Analog Analog Supply Analog Supply Supply Analog Analog Analog Analog Supply Function External resistor to ground sets frequency of oscillator B External resistor to ground sets frequency of oscillator A Digital control of channel 2 (high active) Digital control of channel 2 (low active) Digital control of channel 3 (high active) Digital control of channel 3 (low active) Digital control of channel 4 (high active) Digital control of channel 4 (low active) Enables RF oscillator (high active) Enables output current (high active) +5 V power supply +5 V power supply High: selects IOUTA, RSA, RFA Low: selects IOUTB, RSB, RFA Output current source B for laser diode External resistor to ground sets swing of oscillator B External resistor to ground sets swing of oscillator A Ground Output current source A for laser diode +5 V power supply +5 V power supply Reference current input read channel (input impedance 500 Ω to ground) Reference current input channel 2 (input impedance 500 Ω to ground) Reference current input channel 3 (input impedance 500 Ω to ground) Reference current input channel 4 (input impedance 500 Ω to ground) Ground E4 NE4 ENOSC ENABLE VCC VCC 3 4815AS–DVD–09/04 www.DataSheet4U.com Absolute Maximum Ratings Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Parameters Supply voltage Input voltage at any input Power dissipation Output voltage Junction temperature Storage temperatur.


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