ADN2848 Analog Devices, ADN2848 Datasheet
ADN2848
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ADN2848 Summary of contents
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... Trademarks and registered trademarks are the property of their respective owners. 3.3 V Dual-Loop 50 Mbps to 1.25 Gbps GENERAL DESCRIPTION The ADN2848 uses a unique control algorithm to control both the average power and the extinction ratio of the laser diode (LD) after initial factory setup. External component count and PCB area are low because both power and extinction ratio control are fully integrated ...
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... ADN2848 TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 General Description ......................................................................... 1 Functional Block Diagram .............................................................. 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Absolute Maximum Ratings............................................................ 5 ESD Caution.................................................................................. 5 Pin Configuration and Function Descriptions............................. 6 Theory of Operation ........................................................................ 7 Control........................................................................................... 7 Loop Bandwidth Selection .......................................................... 7 REVISION HISTORY 8/06—Rev Rev. A Updated Format..................................................................Universal Changes to Figure 1.......................................................................... 1 Changes to Specifications ................................................................ 3 Changes to Figure 8 ...
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... Average current V pF μA Average current V kΩ V kΩ Low loop bandwidth selection sec LBWSET = GND sec LBWSET = Data and clock inputs are Ω ac-coupled ps See Figure 2 ps See Figure Internal 30 kΩ pull- A/A A/A − 1.2 V ADN2848 ...
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... ADN2848 Parameter SUPPLY Temperature range is −40°C to +85°C. 2 Measured into a 25 Ω load using a 0-1 pattern at 622 Mbps. 3 When the voltage on DATAP is greater than the voltage on DATAN, the modulation current flows in the IMODP pin. 4 Guaranteed by design and characterization. Not production tested. ...
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... 0.3 V section of this specification is not implied. Exposure to absolute 1.2 V maximum rating conditions for extended periods may affect CC device reliability. −40°C to +85°C −65°C to +150°C 150°C (T Max – T )/θ 32°C/W 300°C Rev Page ADN2848 ...
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... BIAS 32 CCBIAS Connected to Vcc When DC-Coupled to Laser Diode; Connected to I Diode—Current Sink. LBWSET 1 24 IBMON PIN 1 INDICATOR ASET 2 23 IMMON ERSET 3 22 GND3 ADN2848 PSET 4 CC TOP VIEW IMPD 5 20 ALS (Not to Scale) IMPDMON 6 19 FAIL GND4 7 18 DEGRADE ...
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... Figure 4. Laser Transfer Function CONTROL A monitor photodiode, MPD, is required to control the LD. The MPD current is fed into the ADN2848 to control the power and extinction ratio, continuously adjusting the bias current and modulation current in response to the laser’s changing threshold current and light-to-current slope efficiency. ...
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... Z AUTOMATIC LASER SHUTDOWN The ADN2848 ALS allows compliance to ITU-T-G958 (11/94), section 9.7. When ALS is logic high, both the bias and the modulation currents are turned off. Correct operation of ALS is confirmed by the FAIL alarm being raised when ALS is asserted ...
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... POWER CONSUMPTION The ADN2848 die temperature must be kept below 125°C. The LFCSP_VQ package has an exposed paddle. The exposed paddle should be connected in such a manner that the same potential as the ADN2848 ground pins. The θ package is shown under the Absolute Maximum Ratings. Power ...
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... DATAN 1µF PAVCAP ERCAP 9 1µF EACH V AS POSSIBLE TO THE ACTUAL SUPPLY PINS ON THE 8 ADN2848 AND THE LASER DIODE USED. CONSERVATIVE DECOUPLING WOULD INCLUDE 100pF ** ** CAPACITORS IN PARALLEL WITH 10nF CAPACITORS. 1.5kΩ 10nF 10nF 10nF GND Rev Page FAIL ...
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... CC 1µF PAVCAP ERCAP 9 1µF EACH V AS POSSIBLE TO THE ACTUAL SUPPLY PINS ON THE 8 ADN2848 AND THE LASER DIODE USED. CONSERVATIVE DECOUPLING WOULD INCLUDE 100pF ** ** CAPACITORS IN PARALLEL WITH 10nF CAPACITORS. 1.5kΩ 10nF 10nF 10nF GND Figure 11. A 1.244 Mbps Optical Eye. Temperature at 85°C. ...
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... INDICATOR 12° MAX 1.00 0.85 0.80 SEATING PLANE ORDERING GUIDE Model ADN2848ACP-32 ADN2848ACP-32-RL ADN2848ACP-32-RL7 1 ADN2848ACPZ-32 1 ADN2848ACPZ-32-RL 1 ADN2848ACPZ-32-RL7 Pb-free part. ©2006 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. C02746-0-10/06(A) 5.00 BSC SQ 0.60 MAX 24 0.50 BSC TOP 4 ...