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 integrated 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), 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. 4-channel Laser Driver with 2 Outputs, 3 LVDS Inputs and Internal Termination ATR0841 Summary In case of uncertain (balanced) enable signals, a built-in protection circuit keeps the laser diode output current within the defined range. Rev. 4818AS–DVD–09/04 Figure 1. Block Diagram I4 E4 NE4 I3 E3 NE3 Channel 4 Channel 3 IOUTA I2 E2 NE2 IR IOUTB Channel 2 Channel 1 Read Channel ENABLE RF oscillator ENOSC RFA RFB RSA RSB 2 SELA ATR0841 4818AS–DVD–09/04 ATR0841 Pin Configuration I4 I3 I2 IR VCC VCC Figure 2. Pinning QFN24 1 24 23 22 21 20 19 18 IOUTA 2 17 GND 3 16 RSA 4 15 RSB 5 14 IOUTB 6 7 8 13 SELA 9 10 11 12 E4 NE4 ENOSC ENABLE VCC VCC RFB RFA E2 NE2 E3 NE3 Pin Description Pin Symbol Type 1 RFB Analog External resistor to ground sets frequency of oscillator B Function 2 RFA Analog External resistor to ground sets frequency of oscillator A 3 E2 Digital +LVDS control of channel 2 4 NE2 Digital -LVDS control of channel 2 5 E3 Digital +LVDS control of channel 3 6 NE3 Digital -LVDS control of channel 3 7 E4 Digital +LVDS control of channel 4 8 NE4 Digital -LVDS control of channel 4 9 ENOSC Digital Enables RF oscillator (high active) 10 ENABLE Digital Enables output current (high active) 11 VCC Supply +5 V power supply 12 VCC Supply +5 V power supply 13 SELA Digital High: selects IOUTA, RSA, RFA Low: selects IOUTB, RSB, RFB 14 IOUTB Analog Output current source B for laser diode 15 RSB Analog External resistor to ground sets swing of oscillator B 16 RSA Analog External resistor to ground sets swing of oscillator A 17 GND Supply Ground 18 IOUTA Analog Output current source A for laser diode 19 VCC Supply +5 V power supply 20 VCC Supply +5 V power supply 21 IR Analog Reference current input read channel (input impedance 500 Ω to ground) 22 I2 Analog Reference current input channel 2 (input impedance 500 Ω to ground 23 I3 Analog Reference current input channel 3 (input impedance 500 Ω to ground) 24 I4 Analog Reference current input channel 4 (input impedance 500 Ω to ground) Paddle GND Supply Ground 3 4818AS–DVD–09/04 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 Symbol Value Unit Supply voltage VCC -0.5 to +6.1 V Input voltage at any input Vin -0.5 to VCC + 0.5 V Power dissipation Pmax Output voltage (1) 0.7 (2) to 1 W Vout -0.5 to VCC - 1 V Junction temperature Tj 150 °C Storage temperature Tstg -65 to +125 °C Notes: 1. RthJA ≤115 K/W at Tamb = 70° C 2. RthJA ≤115 K/W at Tamb = 25° C Thermal Resistance Parameters Symbol Value Unit RthJA 50(1) K/W Symbol Value Unit VCC 4.5 to 5.9 V IIR, II2, II3, II4 < 1.5 mA External resistor to GND to set oscillator frequency RFA, RFB >3 kΩ External resistor to GND to set oscillator swing RSA, RSB >1 kΩ Tamb 0 to +70 °C Junction ambient, QFN24 Note: 1. Measured with multi-layer test board (JDEC standard) Recommended Operating Range Parameters Supply voltage Input current Operating temperature range 4 ATR0841 4818AS–DVD–09/04 ATR0841 Ordering Information Extended Type Number ATR0841-PFQG Package Lead free QFN24, 4 mm × 4 mm Remarks Taped and reeled Package Information 5 4818AS–DVD–09/04 Atmel Corporation 2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311 Fax: 1(408) 487-2600 Regional Headquarters Europe Atmel Sarl Route des Arsenaux 41 Case Postale 80 CH-1705 Fribourg Switzerland Tel: (41) 26-426-5555 Fax: (41) 26-426-5500 Asia Room 1219 Chinachem Golden Plaza 77 Mody Road Tsimshatsui East Kowloon Hong Kong Tel: (852) 2721-9778 Fax: (852) 2722-1369 Japan 9F, Tonetsu Shinkawa Bldg. 1-24-8 Shinkawa Chuo-ku, Tokyo 104-0033 Japan Tel: (81) 3-3523-3551 Fax: (81) 3-3523-7581 Atmel Operations Memory 2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311 Fax: 1(408) 436-4314 RF/Automotive Theresienstrasse 2 Postfach 3535 74025 Heilbronn, Germany Tel: (49) 71-31-67-0 Fax: (49) 71-31-67-2340 Microcontrollers 2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311 Fax: 1(408) 436-4314 La Chantrerie BP 70602 44306 Nantes Cedex 3, France Tel: (33) 2-40-18-18-18 Fax: (33) 2-40-18-19-60 ASIC/ASSP/Smart Cards 1150 East Cheyenne Mtn. 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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. No licenses to patents or other intellectual property of Atmel are granted by the Company in connection with the sale of Atmel products, expressly or by implication. Atmel’s products are not authorized for use as critical components in life support devices or systems. © Atmel Corporation 2004. All rights reserved. Atmel® and combinations thereof are the registered trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be the trademarks of others. Printed on recycled paper. 4818AS–DVD–09/04