16-Bit, 2 LSB INL, 3 MSPS PulSAR ADC AD7621 FEATURES FUNCTIONAL BLOCK DIAGRAM TEMP REFBUFIN REF REFGND DVDD DGND Throughput 3 MSPS (wideband warp and warp mode) AGND OVDD 2 MSPS (normal mode) AD7621 AVDD OGND 1.25 MSPS (impulse mode) REF REF AMP SERIAL 2.048 V internal reference PORT 16 IN+ Differential input range: V (V up to 2.5 V) SWITCHED REF REF D 15:0 CAP DAC IN INL: 2 LSB maximum, 1 LSB typical SER/PAR PARALLEL INTERFACE BUSY 16-bit resolution with no missing codes PDREF RD CLOCK SINAD: 89 dB typical 100 kHz PDBUF CS THD: 101 dB typical 100 kHz CONTROL LOGIC AND PD OB/2C CALIBRATION CIRCUITRY No pipeline delay (SAR architecture) RESET BYTESWAP Parallel (16- or 8-bit bus) and serial 5 V/3.3 V/2.5 V interface WARP IMPULSE CNVST SPI-/QSPI-/MICROWIRE-/DSP-compatible 2.5 V single-supply operation Figure 1. Power dissipation: 65 mW typical 3 MSPS Table 1. PulSAR Selection 48-lead LQFP and 48-lead LFCSP packages 800 to Speed upgrade of the AD7677 Type/kSPS 100 to 250 500 to 570 1000 >1000 Pseudo AD7651 AD7650/52 AD7653 APPLICATIONS Differential AD7660/61 AD7664/66 AD7667 Medical instruments True Bipolar AD7663 AD7665 AD7671 High speed data acquisition True Digital signal processing Differential AD7675 AD7676 AD7677 AD7621 Communications 18-Bit AD7678 AD7679 AD7674 AD7641 Instrumentation Multichannel/ Spectrum analysis Simultaneous AD7654 AD7655 ATE GENERAL DESCRIPTION PRODUCT HIGHLIGHTS 1. Fast Throughput. The AD7621 is a 16-bit, 3 MSPS, charge redistribution SAR, The AD7621 is a 3 MSPS, charge redistribution, fully differential analog-to-digital converter (ADC) that 16-bit SAR ADC. operates from a single 2.5 V power supply. It contains a high speed 16-bit sampling ADC, an internal conversion clock, an 2. Superior Linearity. internal reference (and buffer), error correction circuits, and The AD7621 has no missing 16-bit code. both serial and parallel system interface ports. It features two 3. Internal Reference. very high sampling rate modes (wideband warp and warp), a The AD7621 has a 2.048 V internal reference with a fast mode (normal) for asynchronous rate applications, and a typical drift of 7 ppm/C. reduced power mode (impulse) for low power applications 4. Single-Supply Operation. where the power is scaled with the throughput. Operation is The AD7621 operates from a 2.5 V single supply and specified from 40C to +85C. typically dissipates 65 mW. In impulse mode, its power dissipation decreases with the throughput. 5. Serial or Parallel Interface. Versatile parallel (16- or 8-bit bus) or 2-wire serial interface 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 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: 781.461.311320052020 Analog Devices, Inc. All rights reserved. 04565-001AD7621 TABLE OF CONTENTS Specifications .................................................................................... 3 Voltage Reference Input ............................................................ 18 Timing Specifications ...................................................................... 5 Power Supply .............................................................................. 19 Serial Clock Timing Specifications ............................................ 6 Power Dissipation vs. Throughput .......................................... 20 Absolute Maximum Ratings ........................................................... 7 Conversion Control ................................................................... 20 ESD Caution.................................................................................. 7 Interfaces ......................................................................................... 21 Pin Configuration and Function Descriptions ............................ 8 Digital Interface .......................................................................... 21 Terminology .................................................................................... 11 Parallel Interface ......................................................................... 21 Typical Performance Characteristics ........................................... 12 Serial Interface ............................................................................ 22 Theory of Operation ...................................................................... 15 Master Serial Interface ............................................................... 22 Circuit Information ................................................................... 15 Slave Serial Interface .................................................................. 24 Converter Operation .................................................................. 15 Microprocessor Interfacing ...................................................... 26 Modes of Operation ................................................................... 15 Application ...................................................................................... 27 Transfer Functions ..................................................................... 16 Layout .......................................................................................... 27 Typical Connection Diagram ................................................... 17 Evaluating the AD7621 Performance ...................................... 27 Analog Inputs ............................................................................. 17 Outline Dimensions ....................................................................... 28 Driver Amplifier Choice ........................................................... 17 Ordering Guide .......................................................................... 29 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 .......................................................... 29 5/2005Revision 0: Initial Version Rev. A Page 2 of 32