Low Power, 16-/24-Bit, Sigma-Delta ADCs Data Sheet AD7788/AD7789 FEATURES FUNCTIONAL BLOCK DIAGRAM REFIN(+) REFIN() GND V DD AD7788: 16-bit resolution AD7789: 24-bit resolution AD7788/ Power AD7789 CLOCK Supply: 2.5 V to 5.25 V operation DOUT/RDY AIN(+) Normal: 75 A maximum SERIAL - DIN INTERFACE ADC* Power-down: 1 A maximum AIN() AND SCLK CONTROL RMS noise: 1.5 V CS LOGIC AD7788: 16-bit p-p resolution AD7789: 19-bit p-p resolution (21.5 bits effective) *AD7788: 16-BIT ADC Integral nonlinearity: 3.5 ppm typical AD7789: 24-BIT ADC Simultaneous 50 Hz and 60 Hz rejection Figure 1. Internal clock oscillator V monitor channel DD 10-lead MSOP INTERFACE 3-wire serial SPI-, QSPI-, MICROWIRE-, and DSP-compatible Schmitt trigger on SCLK APPLICATIONS Smart transmitters Battery applications Portable instrumentation Sensor measurement Temperature measurement Pressure measurement Weigh scales 4 to 20 mA loops GENERAL DESCRIPTION The AD7788/AD7789 are low power, low noise, analog front The devices operate with a single power supply from 2.5 V to ends for low frequency measurement applications. The AD7789 5.25 V. When operating from a 3 V supply, the power dissipation contains a low noise, 24-bit, - analog -to-digital converter for the device is 225 W maximum. The AD7788/AD7789 are (ADC) with one differential input. The AD7788 is a 16-bit available in a 10-lead MSOP. version of the AD7789. The devices operate from an internal clock. Therefore, the user does not have to supply a clock source to the devices. The output data rate is 16.6 Hz, which gives simultaneous 50 Hz/60 Hz rejection. R ev. C 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 20032016 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 03539-001AD7788/AD7789 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Communications Register ......................................................... 11 Interface ............................................................................................. 1 Status Register ............................................................................. 12 Applications ....................................................................................... 1 Mode Register ............................................................................. 13 Functional Block Diagram .............................................................. 1 Data Register ............................................................................... 13 General Description ......................................................................... 1 ADC Circuit Information .............................................................. 14 Revision History ............................................................................... 2 Noise Performance ..................................................................... 14 Specifications ..................................................................................... 3 Digital Interface .......................................................................... 14 AD7789 .......................................................................................... 3 Circuit Description......................................................................... 17 AD7788 .......................................................................................... 4 Analog Input Channel ............................................................... 17 AD7788/AD7789 .......................................................................... 5 Bipolar/Unipolar Configuration .............................................. 17 Timing Characteristics ................................................................ 6 Data Output Coding .................................................................. 17 Timing Diagrams .......................................................................... 7 Reference Input ........................................................................... 17 Absolute Maximum Ratings ............................................................ 8 V Monitor ................................................................................ 18 DD ESD Caution .................................................................................. 8 Grounding and Layout .............................................................. 18 Pin Configuration and Function Descriptions ............................. 9 Outline Dimensions ....................................................................... 19 Typical Performance Characteristics ........................................... 10 Ordering Guide .......................................................................... 19 On-Chip Registers .......................................................................... 11 REVISION HISTORY 4/16Rev. B to Rev. C Change to (RS1, RS0 = 0, 1 Power-On/Reset = 0x02) Section ....... 13 Updated Outline Dimensions ....................................................... 19 Changes to Ordering Guide .......................................................... 19 3/06Rev. A to Rev. B Changes to Ordering Guide .......................................................... 19 11/04Rev. 0 to Rev. A Updated Format .................................................................. Universal Added Footnote 2 to Integral Nonlinearity A Grade ................... 4 Changes to Figure 5 .......................................................................... 9 Updated Outline Dimensions ....................................................... 19 Changes to Ordering Guide .......................................................... 19 8/03Revision 0: Initial Version Rev. C Page 2 of 20