Triple Differential Driver for Wideband Video Data Sheet AD8146/AD8147/AD8148 FEATURES FUNCTIONAL BLOCK DIAGRAMS Triple high speed fully differential driver 700 MHz, 3 dB, 2 V p-p bandwidth (AD8146/AD8148) 24 23 22 21 20 19 600 MHz, 3 dB, 2 V p-p bandwidth (AD8147) OPD 1 18 V C OCM 200 MHz, 0.1 dB, 2 V p-p bandwidth AD8146 V 2 17 S V 3000 V/s slew rate S+ Fixed gain (AD8146/AD8147: G = 2, AD8148: G = 4) IN A 3 16 IN C Differential or single-ended input to differential output +IN A 4 15 +IN C B Can be used as differential-to-differential receiver V 5 A C 14 V S S Drives one or two 100 UTP cables OUT A 6 13 OUT C Adjustable output common-mode voltage (AD8146) 7 8 9 10 11 12 Internal common-mode feedback network Output balance error 50 dB 50 MHz On-chip, sync-on common-mode encoding (AD8147/AD8148) Figure 1. Output pull-down feature for line isolation Low power: 57 mA 5 V for 3 drivers (AD8146) Wide supply voltage range: +5 V to 5 V Available in a small 4 mm 4 mm LFCSP 24 23 22 21 20 19 OPD 1 18 SYNC LEVEL AD8147/ APPLICATIONS AD8148 V (SYNC) 2 17 V S S+ QXGA or 1080p video transmission 2 3 16 IN R IN B KVM networking Video over unshielded twisted pair (UTP) +IN R 4 15 +IN B Differential signal multiplexing B V V 5 14 S S A C OUT R 6 13 OUT B 7 8 9 10 11 12 Figure 2. GENERAL DESCRIPTION The AD8146/AD8147/AD8148 are high speed triple, differential or of 700 MHz and fast slew rates. They have an internal common- single-ended input to differential output drivers. The AD8146 mode feedback feature that provides output amplitude and and AD8147 have a fixed gain of 2, and the AD8148 has a fixed phase matching that is balanced to 60 dB at 50 MHz, suppressing gain of 4. They are all specifically designed for the highest even-order harmonics and minimizing radiated resolution component video signals but can be used for any electromagnetic interference (EMI). type of analog signals or high speed data transmission over The common-mode voltage of each AD8146 output can be set either Category 5 UTP cable or differential printed circuit to any level, allowing transmission of signals over the common- board (PCB) transmission lines. mode voltages. The AD8147 and AD8148 encode the vertical These drivers can be used with the AD8145 triple differential- and horizontal sync signals on the common-mode voltages of to-singled-ended receiver, and the AD8117 crosspoint switch to the outputs. All outputs can be independently set to low voltage states to be used with series diodes for line isolation, allowing produce a video distribution system capable of supporting UXGA or 1080p signals. easy differential multiplexing over the same twisted pair cable. Manufactured on the Analog Devices, Inc. second generation The AD8146/AD8147/AD8148 are available in a 24-lead LFCSP XFCB bipolar process, the drivers have large signal bandwidths and operate over a temperature range of 40C to +85C. Rev. B Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20072014 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. +OUT R V S+ +OUT A V V S+ IN G S+ V IN B S+ +OUT G +IN G +OUT B +IN B OUT G V (SYNC) S OUT B V S V V V V A S+ SYNC S+ OCM +OUT C V B OCM +OUT B H SYNC 09327-001 09327-002AD8146/AD8147/AD8148 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Input Common-Mode Voltage Range in Single-Supply Applications ................................................................................ 15 Applications ....................................................................................... 1 Output Common-Mode Control ............................................. 15 Functional Block Diagrams ............................................................. 1 Sync-On Common-Mode ......................................................... 15 General Description ......................................................................... 1 Applicat ions ..................................................................................... 16 Revision History ............................................................................... 2 Driving RGB Video Signals Over Category-5 UTP Cable .... 16 Specif icat ions ..................................................................................... 3 Video Sync-On Common-Mode .............................................. 16 Absolute Maximum Ratings ............................................................ 7 Driving Two UTP Cables With One Driver ........................... 18 Thermal Resistance ...................................................................... 7 Using the AD8146 as a Receiver ............................................... 18 ESD Caution .................................................................................. 7 Output Pull-Down (OPD) ........................................................ 19 Pin Configurations and Function Descriptions ........................... 8 Layout and Power Supply Decoupling Considerations ......... 19 Typical Performance Characteristics ........................................... 10 Driving a Capacitive Load ......................................................... 19 Theory of Operation ...................................................................... 14 Adding Pre-Emphasis to the AD8148 ...................................... 20 Definition of Terms .................................................................... 14 Exposed Paddle (EP).................................................................. 21 Analyzing an Application Circuit ............................................. 14 Outline Dimensions ....................................................................... 22 Closed-Loop Gain ...................................................................... 14 Ordering Guide .......................................................................... 22 Calculating the Input Impedance ............................................. 15 REVISION HISTORY 3/14Rev. A to Rev. B Changed LFCSP VQ to LFCSP WQ (Throughout) ................... 7 Updated Outline Dimensions ....................................................... 22 Changes to Ordering Guide .......................................................... 22 8/10Rev. 0 to Rev. A Changes to Table 1 ............................................................................ 3 Changes to Table 2 ............................................................................ 5 Changes to Pin Configurations and Function Descriptions Section ................................................................................................ 8 Changes to Adding Pre-Emphasis to the AD8148 Section ....... 20 Updated Outline Dimensions ....................................................... 22 5/07Revision 0: Initial Version Rev. B Page 2 of 24