Dual Pseudo Differential 16-Bit, 1 MSPS PulSAR ADC 12.0 mW in QSOP Data Sheet AD7902 FEATURES GENERAL DESCRIPTION 16-bit resolution with no missing codes The AD7902 is a dual 16-bit, successive approximation, analog- Throughput: 1 MSPS to-digital converter (ADC) that operates from a single power Low power dissipation supply, VDDx, per ADC. It contains two low power, high speed, 7.0 mW at 1 MSPS (V and V only) 16-bit sampling ADCs and a versatile serial port interface (SPI). DD1 DD2 12.0 mW at 1 MSPS (total) On the CNVx rising edge, the AD7902 samples an analog input, 140 W at 10 kSPS IN+, in the range of 0 V to V with respect to a ground sense, REF INL: 1.0 LSB typical, 2.5 LSB maximum IN. The externally applied reference voltage of the REFx pins SINAD: 91 dB at 1 kHz (V ) can be set independently from the supply voltage pins, REF THD: 105 dB at 1 kHz VDDx. The power of the device scales linearly with throughput. Pseudo differential analog input range Using the SDIx inputs, the SPI-compatible serial interface can 0 V to V with V between 2.4 V to 5.1 V REF REF also daisy-chain multiple ADCs on a single 3-wire bus and provide Allows use of any input range an optional busy indicator. It is compatible with 1.8 V, 2.5 V, 3 V, Easy to drive with the ADA4841-1/ADA4841-2 or 5 V logic, using the separate VIOx supplies. No pipeline delay The AD7902 is available in a 20-lead QSOP package with Single-supply 2.5 V operation with 1.8 V/2.5 V/3 V/5 V logic operation specified from 40C to +125C. interface Serial port interface (SPI) QSPI/MICROWIRE/DSP compatible Table 1. MSOP 14-/16-/18-Bit PulSAR ADCs 20-lead QSOP package 400 kSPS to 500 kSPS Wide operating temperature range: 40C to +125C Bits 100 kSPS 250 kSPS 1000 kSPS ADC Driver 1 1 1 18 AD7691 AD7690 AD7982 ADA4941-1 APPLICATIONS ADA4841-1 ADA4841-2 Battery-powered equipment 1 1 1 16 AD7680 AD7685 AD7686 AD7980 ADA4941-1 Communications 1 1 AD7683 AD7687 AD7688 AD7903 ADA4841-1 Automated test equipment (ATE) 1 AD7684 AD7694 AD7693 AD7902 ADA4841-2 Data acquisition 1 1 14 AD7940 AD7942 AD7946 Medical instrumentation 1 Redundant measurement Pin-for-pin compatible. Simultaneous sampling FUNCTIONAL BLOCK DIAGRAM REF = 2.5V TO 5V 2.5V REF1 REF2 VDD1 VDD2 VIO1 VIO1/VIO2 0V TO VREF IN1+ SDI1 SDI1/SDI2 SCK1 SCK1/SCK2 ADC1 CNV1 CNV1/CNV2 IN1 SDO1 SDO1 VIO2 3-WIRE OR 4-WIRE 0V TO VREF IN2+ SDI2 INTERFACE (SPI, CS, AND SCK2 ADC2 CHAIN MODES) CNV2 IN2 SDO2 SDO2 GND AD7902 Figure 1. Rev. B Document Feedback 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. No Tel: 781.329.4700 20142015 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. Technical Support www.analog.com 11756-001AD7902 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Typical Connection Diagram ................................................... 15 Applications ....................................................................................... 1 Analog Inputs ............................................................................. 15 General Description ......................................................................... 1 Driver Amplifier Choice ........................................................... 16 Functional Block Diagram .............................................................. 1 Voltage Reference Input ............................................................ 16 Revision History ............................................................................... 2 Power Supply ............................................................................... 17 Specif icat ions ..................................................................................... 3 Digital Interface .......................................................................... 17 Timing Specifications .................................................................. 5 CS Mode ...................................................................................... 18 Absolute Maximum Ratings ............................................................ 6 Chain Mode ................................................................................ 22 ESD Caution .................................................................................. 6 Applications Information .............................................................. 24 Pin Configuration and Function Descriptions ............................. 7 Simultaneous Sampling ............................................................. 24 Typical Performance Characteristics ............................................. 8 Functional Saftey Considerations ............................................ 25 Terminology .................................................................................... 13 L ayout ............................................................................................... 26 Theory of Operation ...................................................................... 14 Evaluating Performance of the AD7902 .................................. 26 Circuit Information .................................................................... 14 Outline Dimensions ....................................................................... 27 Converter Operation .................................................................. 14 Ordering Guide .......................................................................... 27 REVISION HISTORY 8/15Rev. A to Rev. B Changed ADA4841-x to ADA4841-1/ADA4841-2 .. Throughout Change to Absolute Input Voltage Parameter, Table 2 ................ 3 Changes to Voltage Reference Input Section .............................. 16 Updated Outline Dimensions ....................................................... 27 7/14Rev. 0 to Rev. A Changed Standby Current Unit from nA to A ........................... 4 Changes to Power Supply Section ................................................ 17 2/14Revision 0: Initial Version Rev. B Page 2 of 28