18-Bit, 2 MSPS SAR ADC AD7641 FEATURES FUNCTIONAL BLOCK DIAGRAM TEMP REFBUFIN REF REFGND DVDD DGND Throughput 2 MSPS (wideband warp and warp mode) AGND OVDD 1.5 MSPS (normal mode) AD7641 AVDD OGND INL: 2 LSB typical, 3 LSB max 8 ppm of full scale REF 18-bit resolution with no missing codes REF AMP SERIAL PORT Dynamic range: 95.5 dB 18 IN+ SWITCHED D 17:0 CAP DAC SNR: 93.5 dB typical 20 kHz (V = 2.5 V) REF IN MODE0 PARALLEL THD: 112 dB typical 20 kHz (V = 2.5 V) REF INTERFACE MODE1 2.048 V internal reference: typ drift 10 ppm/C TEMP output PDREF BUSY CLOCK Differential input range: V (V up to 2.5 V) REF REF PDBUF RD CONTROL LOGIC AND No pipeline delay (SAR architecture) PD CS CALIBRATION CIRCUITRY Parallel (18-, 16-, or 8-bit bus) and RESET D0/OB/2C serial 5 V/3.3 V/2.5 V interface SPI/QSPI/MICROWIRE/DSP compatible WARP NORMAL CNVST Single 2.5 V supply operation Figure 1. Power dissipation 75 mW typical 2 MSPS with internal REF Table 1. PulSAR Selection 2 W in power-down mode 100 to 500 to 650 to Pb-free, 48-lead LQFP and 48-lead LFCSP Type/kSPS 250 570 1000 >1000 Speed upgrade of the AD7674, AD7678, AD7679 Pseudo AD7651, AD7650, AD7653, Differential AD7660, AD7652, AD7667 AD7661 AD7664, APPLICATIONS AD7666 True Bipolar AD7610, AD7665 AD7612, Medical instruments AD7663 AD7671 High speed data acquisition/high dynamic data acquisition True AD7675 AD7676 AD7677 AD7621, Digital signal processing Differential AD7622, Spectrum analysis AD7623 Instrumentation 18-Bit AD7631, AD7679 AD7634, AD7641, Communications Multichannel/ AD7678 AD7674 AD7643 ATE Simultaneous AD7654 AD7655 GENERAL DESCRIPTION PRODUCT HIGHLIGHTS 1. Fast Throughput. The AD7641 is an 18-bit, 2 MSPS, charge redistribution SAR, The AD7641 is a 2 MSPS, charge redistribution, fully differential, analog-to-digital converter (ADC) that 18-bit SAR ADC. operates from a single 2.5 V power supply. The part contains a high speed, 18-bit sampling ADC, an internal conversion clock, 2. Superior Linearity. an internal reference (and buffer), error correction circuits, and The AD7641 has no missing 18-bit code. both serial and parallel system interface ports. It features two 3. Internal Reference. very high sampling rate modes (wideband warp and warp) and The AD7641 has a 2.048 V internal reference with a typical a fast mode (normal) for asynchronous rate applications. The drift of 10 ppm/C and an on-chip TEMP sensor. AD7641 is hardware factory calibrated and tested to ensure ac 4. Single-Supply Operation. parameters, such as signal-to-noise ratio (SNR), in addition to The AD7641 operates from a 2.5 V single supply. the more traditional dc parameters of gain, offset, and linearity. 5. Serial or Parallel Interface. The AD7641 is available in Pb-free only packages with Versatile parallel (16- or 8-bit bus) or 2-wire serial interface operation specified from 40C to +85C. arrangement compatible with 2.5 V, 3.3 V, or 5 V logic. Rev. A 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. Tel: 781.329.4700 www.analog.com No license is granted by implication or otherwise under any patent or patent rights of Analog Fax: 781.461.3113 20062020 Analog Devices, Inc. All rights reserved. Devices. Trademarks and registered trademarks are the property of their respective owners. 04761-001AD7641 TABLE OF CONTENTS Features .............................................................................................. 1 Analog Inputs ............................................................................. 18 Applications ...................................................................................... 1 Multiplexed Inputs ..................................................................... 18 General Description ......................................................................... 1 Driver Amplifier Choice ........................................................... 18 Functional Block Diagram .............................................................. 1 Voltage Reference Input ............................................................ 19 Product Highlights ........................................................................... 1 Power Supply .............................................................................. 21 Revision History ............................................................................... 2 Conversion Control ................................................................... 21 Specifications .................................................................................... 3 Interfaces ......................................................................................... 22 Timing Specifications ...................................................................... 5 Digital Interface .......................................................................... 22 Absolute Maximum Ratings ........................................................... 7 Parallel Interface ......................................................................... 22 ESD Caution.................................................................................. 7 Serial interface ............................................................................ 23 Pin Configuration and Function Descriptions ............................ 8 Master Serial Interface ............................................................... 23 Terminology .................................................................................... 12 Slave Serial Interface .................................................................. 25 Typical Performance Characteristics ........................................... 13 Microprocessor Interfacing ...................................................... 27 Appplications Information ........................................................... 16 Application Hints ........................................................................... 28 Circuit Information ................................................................... 16 Layout .......................................................................................... 28 Converter Operation .................................................................. 16 Evaluating the AD7641 Performance ...................................... 28 Modes of Operation ................................................................... 16 Outline Dimensions ....................................................................... 29 Transfer Functions ..................................................................... 17 Ordering Guide .......................................................................... 29 Typical Connection Diagram ....................................................... 18 REVISION HISTORY 8/2020Rev. 0 to Rev. A Changed CP-48-1 to CP-48-4 ...................................... Throughout Added Figure 4 Renumbered Sequentially .................................. 8 Updated Outline Dimensions ....................................................... 28 Changes to Ordering Guide .......................................................... 28 1/2006Revision 0: Initial Version Rev. A Page 2 of 29