High Speed Oversampling CMOS ADC with 16-Bit Resolution at a 2.5 MHz Output Word Rate AD9260 FUNCTIONAL BLOCK DIAGRAM FEATURES Monolithic 16-bit, oversampled A/D converter 8 oversampling mode, 20 MSPS clock RESET/ SYNC DVSS DVDD 2.5 MHz output word rate 1.01 MHz signal passband with 0.004 dB ripple VINA MULTIBIT DIGITAL OTR Signal-to-noise ratio: 88.5 dB SIGMA-DELTA DEMODULATOR MODULATOR Total harmonic distortion: 96 dB VINB 12-BIT: 20MHz Spurious-free dynamic range: 100 dB STAGE 1:2X 16-BIT: Input referred noise: 0.6 LSB DECIMATION 10MHz FILTER Selectable oversampling ratio: 1, 2, 4, 8 AD9260 BIT1 Selectable power dissipation: 150 mW to 585 mW BIT16 STAGE 2:2X 16-BIT: 85 dB stop-band attenuation DECIMATION 5MHz REF TOP FILTER 0.004 dB pass-band ripple REF REFERENCE BOTTOM BUFFER Linear phase COMMON STAGE 3:2X 16-BIT: MODE Single 5 V analog supply, 5 V/3 V digital supply DECIMATION 2.5MHz FILTER Synchronize capability for parallel ADC interface VREF DAV BANDGAP Twos complement output data SENSE BIAS CLOCK MODE READ REFERENCE CIRCUIT BUFFER REGISTER 44-lead MQFP REFCOM PRODUCT DESCRIPTION BIAS ADJUST CLK MODE CS The AD9260 is a 16-bit, high-speed oversampled analog-to- Figure 1. digital converter (ADC) that offers exceptional dynamic range over a wide bandwidth. The AD9260 is manufactured on an tion levels as low as 150 mW at reduced clock and data rates. advanced CMOS process. High dynamic range is achieved with The AD9260 is available in a 44-lead MQFP package and is an oversampling ratio of 8 through the use of a proprietary specified to operate over the industrial temperature range. technique that combines the advantages of sigma-delta and PRODUCT HIGHLIGHTS pipeline converter technologies. The AD9260 is a switched- The AD9260 is fabricated on a very cost effective CMOS capacitor ADC with a nominal full-scale input range of 4 V. It process. High speed, precision, mixed-signal analog circuits are offers a differential input with 60 dB of common-mode rejec- combined with high density digital filter circuits. The AD9260 tion of common-mode signals. The signal range of each differ- offers a complete single-chip 16-bit sampling ADC with a 2.5 ential input is 1 V centered on a 2.0 V common-mode level. MHz output data rate in a 44-lead MQFP. The on-chip decimation filter is configured for maximum Selectable Internal Decimation FilteringThe AD9260 performance and flexibility. A series of three half-band FIR provides a high performance decimation filter with 0.004 dB filter stages provide 8 decimation filtering with 85 dB of stop- pass-band ripple and 85 dB of stop-band attenuation. The filter band attenuation and 0.004 dB of pass-band ripple. An onboard is configurable with options for 1, 2, 4, and 8 decimation. digital multiplexer allows the user to access data from the various stages of the decimation filter. The on-chip Power ScalingThe AD9260 consumes a low 585 mW of programmable reference and reference buffer amplifier are power at 16-bit resolution and 2.5 MHz output data rate. Its configured for maximum accuracy and flexibility. An external power can be scaled down to as low as 150 mW at reduced reference can also be chosen to suit the users specific dc clock rates. accuracy and drift requirements. Single SupplyBoth the analog and digital portions of the The AD9260 operates on a single +5 V supply, typically AD9260 can operate off of a single +5 V supply, simplifying consuming 585 mW of power. A power scaling circuit is system power supply design. The digital logic will also provided allowing the AD9260 to operate at power consump- accommodate a single +3 V supply for reduced power. Rev. C 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. 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AVDD AVSS AVDD AVSS AVDD AVSS OUTPUT MODE MULTIPLEXER DRVDD OUTPUT REGISTER DRVSS 00581-C-001AD9260 TABLE OF CONTENTS Specifications..................................................................................... 3 Theory of Operation ...................................................................... 23 Clock Input Frequency Range .................................................... 3 Analog Input and Reference Overview ....................................... 24 DC Specifications ......................................................................... 3 Input Span ................................................................................... 24 AC Specifications.......................................................................... 4 Input Compliance Range........................................................... 24 Digital Filter Characteristics ....................................................... 6 Analog Input Operation............................................................ 24 Digital Filter Characteristics ....................................................... 7 Driving the Input........................................................................ 25 Digital Specifications ................................................................... 9 Reference Operation ...................................................................... 28 Switching Specifications ............................................................ 10 Digital Inputs and Outputs ........................................................... 30 Absolute Maximum Ratings.......................................................... 11 Digital Outputs ........................................................................... 30 Thermal Characteristics ............................................................ 11 Mode Operation ......................................................................... 31 ESD Caution................................................................................ 11 Bias Pin Operation ..................................................................... 32 Terminology .................................................................................... 12 Power Dissipation Considerations............................................... 33 Pin Configuration and Function Descriptions........................... 13 Digital Output Driver Considerations (DRVDD) ................. 33 Typical Performance Characteristics ........................................... 14 Grounding and Decoupling...................................................... 34 Typical AC Characterization Curves Evaluation Board General Description ....................................... 36 vs. Decimation Mode................................................................. 15 Features and User Controls....................................................... 36 Typical AC Characterization Curves for 8 Mode ................ 16 Shipment Configuration............................................................ 37 Typical AC Characterization Curves for 4 Mode ................ 17 Quick Setup................................................................................. 37 Typical AC Characterization Curves for 2 Mode ................ 18 Application Information ........................................................... 38 Typical AC Characterization Curves for 1 Mode ................ 19 Outline Dimensions ....................................................................... 43 Typical AC Characterization Curves ....................................... 20 Ordering Guide .......................................................................... 43 Additional AC Characterization Curves ................................. 21 REVISION HISTORY 7/04Changed from Rev. B to Rev. C Changed trimpot to variable resistor ..................... Universal Updated Format................................................................ Universal Updated Outline Dimensions ......................................................43 Changes to Ordering Guide .........................................................43 5/00Changed from Rev. A to Rev. B. 1/98Changed from Rev. 0 to Rev. A. Rev. C Page 2 of 44