Triple Differential Receiver with 200 Meter Adjustable Cable Equalization Data Sheet AD8124 FEATURES FUNCTIONAL BLOCK DIAGRAM V V V V PEAK POLE OFFSET GAIN Compensates cables to 200 meters for wideband video All resolutions through UXGA AD8124 Fast rise and fall times 8 ns with 2 V step at 200 meters of UTP cable IN R OUT R 37 dB peak gain at 100 MHz +IN R Two frequency response gain adjustment pins IN High frequency peaking adjustment (V ) G PEAK OUT G Broadband flat gain adjustment (V ) GAIN +IN G Pole location adjustment pin (V ) POLE IN B Compensates for variations between cables OUT B +IN Can be optimized for either UTP or coaxial cable B DC output offset adjust (V ) OFFSET IN CMP1 Low output offset voltage: 24 mV OUT CMP1 +IN CMP1 Compensates both RGB and YPbPr IN Two on-chip comparators with hysteresis CMP2 OUT CMP2 Can be used for common-mode sync extraction +IN CMP2 Available in 40-lead, 6 mm 6 mm LFCSP Figure 1. APPLICATIONS Keyboard-video-mouse (KVM) Digital signage RGB video over UTP cables Professional video projection and distribution HD video Security video GENERAL DESCRIPTION The AD8124 is a triple, high speed, differential receiver and The AD8124 has three control pins for optimal cable equalizer that compensates for the transmission losses of UTP compensation, as well as an output offset adjust pin. Two and coaxial cables up to 200 meters in length. Various gain stages voltage-controlled pins are used to compensate for different are summed together to best approximate the inverse frequency cable lengths the VPEAK pin controls the amount of high frequency response of the cable. Logic circuitry inside the AD8124 controls peaking and the V pin adjusts the broadband flat gain, which GAIN the gain functions of the individual stages so that the lowest compensates for the low frequency flat cable loss. noise can be achieved at short-to-medium cable lengths. This For added flexibility, an optional pole adjustment pin, V , POLE technique optimizes its performance for low noise, short-to- allows movement of the pole locations, allowing for the medium range applications, while at the same time provides compensation of different gauges and types of cable as well the high gain bandwidth required for longer cable equalization as variations between different cables and/or equalizers. The (up to 200 meters). Each channel features a high impedance VOFFSET pin allows the dc voltage at the output to be adjusted, differential input that is ideal for interfacing directly with the cable. adding flexibility for dc-coupled systems. The AD8124 is available in a 6 mm 6 mm, 40-lead LFCSP and is rated to operate over the extended temperature range of 40C to +85C. Rev. A 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 20112015 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. 09601-001AD8124 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Applications Information .............................................................. 11 Applications ....................................................................................... 1 Basic Operation .......................................................................... 11 Functional Block Diagram .............................................................. 1 Comparators ............................................................................... 11 General Description ......................................................................... 1 Sync Pulse Extraction Using Comparators ............................. 12 Revision History ............................................................................... 2 Using the V , V , V , and V Inputs ................... 12 PEAK POLE GAIN OFFSET Specifications ..................................................................................... 3 Using the AD8124 with Coaxial Cable .................................... 13 Absolute Maximum Ratings ............................................................ 5 Driving 75 Video Cable with the AD8124 .......................... 13 Thermal Resistance ...................................................................... 5 Driving a Capacitive Load ......................................................... 13 Maximum Power Dissipation ..................................................... 5 Power Supply Filtering ............................................................... 13 ESD Caution .................................................................................. 5 Layout and Power Supply Decoupling Considerations ......... 14 Pin Configuration and Function Description .............................. 6 Power-Down ............................................................................... 14 Typical Performance Characteristics ............................................. 7 Outline Dimensions ....................................................................... 15 Theory of Operation ...................................................................... 10 Ordering Guide .......................................................................... 15 Input Common-Mode Voltage Range Considerations ......... 10 REVISION HISTORY 12/15Rev. 0 to Rev. A Changes to Figure 3 .......................................................................... 6 Updated Outline Dimensions ....................................................... 15 Changes to Ordering Guide .......................................................... 15 1/11Revision 0: Initial Version Rev. A Page 2 of 15