Quad, 235 MHz, DC-Coupled VGA and Differential Output Amplifier Data Sheet AD8264 FEATURES GENERAL DESCRIPTION Low noise The AD8264 is a quad, linear-in-dB, general-purpose, variable Voltage noise: 2.3 nV/Hz gain amplifier (VGA) with a preamplifier (preamp), and a flexible Current noise: 2 pA/Hz differential output buffer. DC coupling, combined with wide Wide bandwidth bandwidth, makes this amplifier a very good pulse processor. Small signal: 235 MHz (VGAx) 80 MHz (output amplifier) Each channel includes a single-ended input preamp/VGA section Large signal: 80 MHz (1 V p-p) to preserve the wide bandwidth and fast slew rate for low dis- Gain range tortion pulse applications. A 6 dB differential output buffer with 0 to 24 dB (input to VGA output) common-mode and offset adjustments enable direct coupling to 6 to 30 dB (input to differential output) most modern high speed analog-to-digital converters (ADCs), Gain scaling: 20 dB/V using the converter reference output for perfect dc matching levels. DC-coupled The 3 dB bandwidth of the preamp/VGA is dc to 235 MHz, Single-ended input and differential output and the bandwidth of the differential driver is 80 MHz. The Supplies: 2.5 V to 5 V floating gain control interface provides a precise linear-in-dB scale Low power: 140 mW per channel at 3.3 V of 20 dB/V and is easy to interface to a variety of external circuits. The gain of each channel is adjusted independently, and all APPLICATIONS channels are referenced to a single pin, GNLO. Combined with Multichannel data acquisition a multioutput, digital-to-analog converter (DAC), each section Positron emission tomography of the AD8264 can be used for active calibration or as a trim Gain trim amplifier. Industrial and medical ultrasound Radar receivers Operation from a bipolar power supply enables amplification of negative voltage pulses generated by current-sinking pulses into a grounded load, such as is typical of photodiodes or photo- multiplier tubes (PMT). Delay-free processing of wideband video signals is also possible. FUNCTIONAL BLOCK DIAGRAM ONE CHANNEL SHOWN OPPx VGAx PREAMP FIXED GAIN VGA DIFFERENTIAL OUTPUT AMPLIFIER AMPLIFIER 6dB (2) 6dB (2) 18dB (8) IPPx 1k 2k + ATTENUATOR IPNx 100 24dB TO 0dB 747 VOLx 100 107 VOHx GAIN INTERPOLATOR INTERFACE VPOS 2k BIAS VNEG 1k COMM GNHx GNLO VOCM OFSx Figure 1. Rev. C 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 20092018 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. 07736-001AD8264 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Overview ..................................................................................... 28 Applications ....................................................................................... 1 Preamp ......................................................................................... 28 General Description ......................................................................... 1 VGA ............................................................................................. 28 Functional Block Diagram .............................................................. 1 Post Amplifier ............................................................................. 29 Revision History ............................................................................... 2 Noise ............................................................................................ 29 Specifications ..................................................................................... 3 Applications Information .............................................................. 30 Absolute Maximum Ratings ............................................................ 6 A Low Channel Count Application Concept Using a Discrete Reference ..................................................................................... 30 Thermal Resistance ...................................................................... 6 A DC Connected Concept Example ........................................ 31 Maximum Power Dissipation ..................................................... 6 Evaluation Board ............................................................................ 34 ESD Caution .................................................................................. 6 Connecting and Using the AD8264-EVALZ .......................... 34 Pin Configuration and Function Descriptions ............................. 7 Outline Dimensions ....................................................................... 37 Typical Performance Characteristics ............................................. 8 Ordering Guide .......................................................................... 37 Test Circuits ..................................................................................... 20 Theory of Operation ...................................................................... 28 REVISION HISTORY 10/2018Rev. B to Rev. C 1/2011Rev. 0 to Rev. A Deleted Figure 113 .......................................................................... 31 Changes to Figure 1 ........................................................................... 1 Added Figure 113 Renumbered Sequentially ............................ 31 Changes to Connecting and Using the AD8264-EVALZ Section Updated Outline Dimensions ....................................................... 37 and Figure 117 ................................................................................ 34 Changes to Figure 118 ................................................................... 35 1/2016Rev. A to Rev. B Changes to Features Section, General Description Section, and 5/2009Revision 0: Initial Version Figure 1 .............................................................................................. 1 Changes to Figure 2 .......................................................................... 7 Changes to VGA Section ............................................................... 28 Updated Outline Dimensions ....................................................... 37 Changes to Ordering Guide .......................................................... 37 Rev. C Page 2 of 37