Dual Differential 16-Bit, 1 MSPS PulSAR ADC 12.0 mW in QSOP Data Sheet AD7903 FEATURES GENERAL DESCRIPTION 16-bit resolution with no missing codes The AD7903 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) DD1 DD2 16-bit sampling ADCs and a versatile serial port interface (SPI). 12.0 mW at 1 MSPS (total) On the CNVx rising edge, the AD7903 samples the voltage 140 W at 10 kSPS difference between the INx+ and INx pins. The voltages on INL: 0.5 LSB typical, 2.0 LSB maximum these pins usually swing in opposite phases between 0 V and SINAD: 93.5 dB at 1 kHz V . The externally applied reference voltage of the REFx pins REF THD: 112 dB at 1 kHz (V ) can be set independently from the supply voltage pins, REF True differential analog input range: V REF VDDx. The power of the device scales linearly with throughput. 0 V to V with V between 2.4 V to 5.1 V REF REF Using the SDIx inputs, the SPI-compatible serial interface can Allows use of any input range also daisy-chain multiple ADCs on a single 3-wire bus and provide Easy to drive with the ADA4941-1 an optional busy indicator. It is compatible with 1.8 V, 2.5 V, 3 V, No pipeline delay or 5 V logic, using the separate VIOx supplies. Single-supply 2.5 V operation with 1.8 V/2.5 V/3 V/5 V logic The AD7903 is available in a 20-lead QSOP package with operation interface specified from 40C to +125C. Serial port interface (SPI)/QSPI/MICROWIRE/DSP compatible 20-lead QSOP package Table 1. MSOP 14-/16-/18-Bit PulSAR ADCs Wide operating temperature range: 40C to +125C 100 250 400 kSPS 1000 ADC Bits kSPS kSPS to 500 kSPS kSPS Driver APPLICATIONS 1 1 1 18 AD7691 AD7690 AD7982 ADA4941-1 Battery-powered equipment ADA4841-x 1 1 1 16 AD7680 AD7685 AD7686 AD7980 ADA4941-1 Communications 1 1 AD7683 AD7687 AD7688 AD7903 ADA4841-x Automated test equipment (ATE) 1 AD7684 AD7694 AD7693 AD7902 Data acquisition 1 1 14 AD7940 AD7942 AD7946 Medical instrumentation Redundant measurement 1 Pin-for-pin compatible. Simultaneous sampling FUNCTIONAL BLOCK DIAGRAM REF = 2.5V TO 5V 2.5V REF1 REF2 VDD1 VDD2 ADA4941-1 VIO1 VIO1/VIO2 REF IN1+ SDI1 SDI1/SDI2 ADC1 SCK1 SCK1/SCK2 CNV1 CNV1/CNV2 10V, 5V, ... IN1 SDO1 SDO1 ADA4941-1 VIO2 3-WIRE OR 4-WIRE REF IN2+ SDI2 INTERFACE (SPI, CS, AND ADC2 SCK2 CHAIN MODES) CNV2 10V, 5V, ... IN2 SDO2 SDO2 GND AD7903 Figure 1. Rev. B Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. 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Technical Support www.analog.com 11755-001AD7903 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Analog Inputs.............................................................................. 15 Applications ....................................................................................... 1 Driver Amplifier Choice ........................................................... 16 General Description ......................................................................... 1 Single-to-Differential Driver .................................................... 16 Functional Block Diagram .............................................................. 1 Voltage Reference Input ............................................................ 17 Revision History ............................................................................... 2 Power Supply ............................................................................... 17 Specifications ..................................................................................... 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 Safety Considerations ............................................ 25 Terminology .................................................................................... 13 Layout ............................................................................................... 26 Theory of Operation ...................................................................... 14 Evaluating Performance of the AD7903.................................. 26 Circuit Information .................................................................... 14 Outline Dimensions ....................................................................... 27 Converter Operation .................................................................. 14 Ordering Guide .......................................................................... 27 Typical Connection Diagram.................................................... 15 REVISION HISTORY 8/14Rev. A to Rev. B Changed Standby Current Unit from nA to A ........................... 4 Changes to Power Supply Section ................................................ 17 1/14Rev. 0 to Rev. A Change to Gain Error Temperature Drift Parameter .................. 3 Changes to Figure 12 ........................................................................ 9 Changes to Figure 17 and Figure 20............................................. 10 Changes to Figure 28 ...................................................................... 11 12/13Revision 0: Initial Version Rev. B Page 2 of 28