16-Bit, Low Power, Sigma-Delta ADC Data Sheet AD7171 FEATURES FUNCTIONAL BLOCK DIAGRAM GND V REFIN(+) REFIN() DD Output data rate: 125 Hz Pin-programmable power-down and reset AIN(+) DOUT/RDY Status function 16-BIT - ADC AIN() SCLK Internal clock oscillator Current: 135 A PDRST INTERNAL AD7171 Power supply: 2.7 V to 5.25 V CLOCK 40C to +105C temperature range Package: 10-lead 3 mm 3 mm LFCSP Figure 1. INTERFACE Table 1. VREF = VDD RMS Noise P-P Noise P-P Resolution ENOB 2-wire serial (read-only device) 5 V 11.5 V 76 V 16 bits 16 bits SPI compatible 3 V 6.9 V 45 V 16 bits 16 bits Schmitt trigger on SCLK APPLICATIONS Weigh scales Pressure measurement Industrial process control Portable instrumentation GENERAL DESCRIPTION The AD7171 is a very low power, 16-bit, analog-to-digital The output data rate of the AD7171 is 125 Hz, whereas the settling converter (ADC). It contains a precision, 16-bit, - ADC and time is 24 ms. The AD7171 has one differential input and a gain an on-chip oscillator. Consuming only 135 A, the AD7171 is of 1. This is useful in applications where the user needs to use an particularly suitable for portable or battery operated products external amplifier to implement system-specific filtering or gain where very low power is a requirement. The AD7171 also has a requirements. power-down mode in which the device consumes 5 A, thus The AD7171 operates with a power supply from 2.7 V to 5.25 V. increasing the battery life of the product. It is available in a 10-lead LFCSP. For ease of use, dedicated pins control all of the features of the The AD7170 is a 12-bit version of the AD7171. It has the same AD7171. Each time a data read occurs, eight status bits are feature set as the AD7171 and is pin-for-pin compatible. appended to the 16-bit conversion. These status bits contain a pattern sequence that can be used to confirm the validity of the serial transfer. Rev. 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 20092016 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. 08417-001AD7171 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Overview ..................................................................................... 10 Interface ............................................................................................. 1 Filter, Data Rate, and Settling Time ......................................... 10 Applications ....................................................................................... 1 Gain .............................................................................................. 10 Functional Block Diagram .............................................................. 1 Power-Down/Reset (PDRST) ................................................... 10 General Description ......................................................................... 1 Analog Input Channel ............................................................... 10 Revision History ............................................................................... 2 Bipolar Configuration ................................................................ 10 Specifications ..................................................................................... 3 Data Output Coding .................................................................. 11 Timing Characteristics ................................................................ 5 Reference ..................................................................................... 11 Timing Diagrams ..................................................................... 5 Digital Interface .......................................................................... 11 Absolute Maximum Ratings ............................................................ 6 Grounding and Layout .............................................................. 12 Thermal Resistance ...................................................................... 6 Applications Information .............................................................. 13 ESD Caution .................................................................................. 6 Temperature System ................................................................... 13 Pin Configuration and Function Descriptions ............................. 7 Signal Conditioning Circuit ...................................................... 13 Typical Performance Characteristics ............................................. 8 Outline Dimensions ....................................................................... 14 Output Noise and Resolution Specifications ................................ 9 Ordering Guide .......................................................................... 14 ADC Circuit Information .............................................................. 10 REVISION HISTORY 6/2016Rev. B to Rev. C Change to Figure 14 ....................................................................... 13 6/2015Rev. A to Rev. B Added Table Number Renumbered Sequentially ........................ 1 Changed NC Pin (Pin 10) to GND Pin (Pin 10), Figure 5 .......... 7 4/2013Rev. 0 to Rev. A Changes to Filter, Data Rate, and Settling Time Section ........... 10 Changes to Temperature System Section .................................... 13 Updated Outline Dimensions ....................................................... 14 Changes to Ordering Guide .......................................................... 14 10/2009Revision 0: Initial Version Rev. C Page 2 of 16