8-Bit, 250 MSPS 3.3 V A/D Converter AD9481 FEATURES FUNCTIONAL BLOCK DIAGRAM VREF SENSE AGND DRGND DRVDD AVDD DNL = 0.35 LSB INL = 0.26 LSB AD9481 Single 3.3 V supply operation (3.0 V to 3.6 V) REFERENCE 8 PORT Power dissipation of 439 mW at 250 MSPS D7A TO D0A A 1 V p-p analog input range VIN+ 8-BIT T AND H 8 Internal 1.0 V reference ADC VIN PIPELINE Single-ended or differential analog inputs PORT 8 CORE DS+ D7B TO D0B B De-multiplexed CMOS outputs DS Power-down mode CLK+ CLOCK DCO+ Clock duty cycle stabilizer MGMT CLK DCO LOGIC APPLICATIONS Digital oscilloscopes PDWN S1 Instrumentation and measurement Figure 1. Communications Point-to-point radios Digital predistortion loops The AD9481 is available in a Pb-free, 44-lead, surface-mount GENERAL DESCRIPTION package (TQFP-44) specified over the industrial temperature The AD9481 is an 8-bit, monolithic analog-to-digital converter range (40C to +85C). (ADC) optimized for high speed and low power consumption. Small in size and easy to use, the product operates at a PRODUCT HIGHLIGHTS 250 MSPS conversion rate, with excellent linearity and dynamic 1. Superior linearity. A DNL of 0.35 makes the AD9481 performance over its full operating range. suitable for many instrumentation and measurement To minimize system cost and power dissipation, the AD9481 applications includes an internal reference and track-and-hold circuit. The 2. Power-down mode. A power-down function may be exercised user only provides a 3.3 V power supply and a differential to bring total consumption down to 15 mW. encode clock. No external reference or driver components are required for many applications. 3. De-multiplexed CMOS outputs allow for easy interfacing with low cost FPGAs and standard logic. The digital outputs are TTL/CMOS-compatible with an option of twos complement or binary output format. The output data bits are provided in an interleaved fashion along with output clocks that simplifies data capture. Rev. 0 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 rights of third parties that may result from its use. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Specifications subject to change without notice. No license is granted by implication Tel: 781.329.4700 www.analog.com or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Fax: 781.326.8703 2004 Analog Devices, Inc. All rights reserved. 05045-001AD9481 TABLE OF CONTENTS DC Specifications ............................................................................. 3 Data Clock Out........................................................................... 20 Digital Specifications........................................................................ 4 Power-Down Input..................................................................... 20 AC Specifications.............................................................................. 5 AD9481 Evaluation Board ............................................................ 21 Switching Specifications .................................................................. 6 Power Connector........................................................................ 21 Timing Diagram ........................................................................... 7 Analog Inputs.............................................................................. 21 Absolute Maximum Ratings............................................................ 8 Gain.............................................................................................. 21 Explanation of Test Levels........................................................... 8 Optional Operational Amplifier............................................... 21 ESD Caution.................................................................................. 8 Clock ............................................................................................ 21 Pin Configuration and Function Descriptions............................. 9 Optional Clock Buffer ............................................................... 21 Terminology .................................................................................... 10 DS ................................................................................................. 21 Typical Performance Characteristics ........................................... 12 Optional XTAL ........................................................................... 22 Equivalent Circuits ......................................................................... 16 Voltage Reference ....................................................................... 22 Applications..................................................................................... 17 Data Outputs............................................................................... 22 Analog Inputs.............................................................................. 17 Evaluation Board Bill of Materials (BOM) ................................. 23 Voltage Reference ....................................................................... 17 PCB Schematics .............................................................................. 24 Clocking the AD9481................................................................. 19 PCB Layers ...................................................................................... 26 DS Inputs ..................................................................................... 19 Outline Dimensions ....................................................................... 28 Digital Outputs ........................................................................... 20 Ordering Guide .......................................................................... 28 Interleaving Two AD9481s........................................................ 20 REVISION HISTORY 10/04Revision 0: Initial Version Rev. 0 Page 2 of 28