16-Bit 100 kSPS PulSAR Unipolar ADC with Reference AD7661 FUNCTIONAL BLOCK DIAGRAM FEATURES REFBUFIN REF REFGND DVDD DGND 2.5 V internal reference: typical drift 3 ppm/C Guaranteed max drift 15 ppm/C OVDD AGND AD7661 Throughput: 100 kSPS AVDD OGND SERIAL REF INL: 2.5 LSB max (0.0038% of full scale) PORT 16 16-bit resolution with no missing codes IN SWITCHED DATA 15:0 CAP DAC S/(N+D): 88 dB min 20 kHz INGND BUSY PARALLEL THD: 96 dB max 20 kHz PDREF INTERFACE RD PDBUF Analog input voltage range: 0 V to 2.5 V CLOCK CS PD Both AC and DC specifications CONTROL LOGIC AND SER/PAR RESET CALIBRATION CIRCUITRY No pipeline delay OB/2C Parallel and serial 5 V/3 V interface BYTESWAP TM TM SPI/QSPI /MICROWIRE /DSP compatible CNVST Single 5 V supply operation Figure 1. Functional Block Diagram Power dissipation 16 mW typ, 160 W 1 kSPS without REF Table 1. PulSAR Selection 40 mW typ with REF 800 48-lead LQFP and 48-lead LFCSP packages Type/kSPS 100250 500570 1000 Pin-to-pin compatible with PulSAR ADCs Pseudo- AD7651 AD7650/AD7652 AD7653 Differential AD7660/AD7661 AD7664/AD7666 AD7667 APPLICATIONS True Bipolar AD7663 AD7665 AD7671 Data acquisition True AD7675 AD7676 AD7677 Medical instruments Differential Digital signal processing 18-Bit AD7678 AD7679 AD7674 Spectrum analysis Multichannel/ AD7654 Simultaneous Instrumentation AD7655 Battery-powered systems Process control PRODUCT HIGHLIGHTS 1. Fast Throughput. The AD7661 is a 100 kSPS, charge redistribution, 16-bit GENERAL DESCRIPTION SAR ADC with internal error correction circuitry. The AD7661 is a 16-bit, 100 kSPS, charge redistribution SAR 2. Superior INL. analog-to-digital converter that operates from a single 5 V The AD7661 has a maximum integral nonlinearity of power supply. The part contains a high speed 16-bit sampling 2.5 LSB with no missing 16-bit codes. ADC, an internal conversion clock, internal reference, error correction circuits, and both serial and parallel system inter- 3. Internal Reference. face ports. The AD7661 is hardware factory-calibrated and The AD7661 has an internal reference with a typical comprehensively tested to ensure ac parameters such as signal- temperature drift of 3 ppm/C. to-noise ratio (SNR) and total harmonic distortion (THD), in 4. Single-Supply Operation. addition to the more traditional dc parameters of gain, offset, The AD7661 operates from a single 5 V supply. Its power and linearity. dissipation decreases with throughput. The AD7661 is available in a 48-lead LQFP and a tiny 48-lead 5. Serial or Parallel Interface. LFCSP with operation specified from 40C to +85C. Versatile parallel or 2-wire serial interface arrangement is compatible with both 3 V and 5 V logic. 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 2003 Analog Devices, Inc. All rights reserved. 03033-0-001AD7661 TABLE OF CONTENTS Specifications..................................................................................... 3 Digital Interface.......................................................................... 22 Timing Specifications....................................................................... 5 Parallel Interface......................................................................... 22 Absolute Maximum Ratings............................................................ 7 Serial Interface ............................................................................ 22 ESD Caution.................................................................................. 7 Master Serial Interface............................................................... 23 Pin Configuration and Function Descriptions............................. 8 Slave Serial Interface .................................................................. 24 Definitions of Specifications ......................................................... 11 Microprocessor Interfacing....................................................... 26 Typical Performance Characteristics ........................................... 12 Application Hints ........................................................................... 27 Circuit Information........................................................................ 16 Bipolar and Wider Input Ranges.............................................. 27 Converter Operation.................................................................. 16 Layout .......................................................................................... 27 Typical Connection Diagram ................................................... 18 Evaluating the AD7661s Performance .................................... 27 Power Dissipation versus Throughput .................................... 20 Outline Dimensions ....................................................................... 28 Conversion Control.................................................................... 21 Ordering Guide .......................................................................... 28 REVISION HISTORY Revision 0: Initial Version. 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