Low Power, 8-/16-Channel, 31.25 kSPS, 24-Bit, Highly Integrated Sigma-Delta ADC Data Sheet AD7173-8 FEATURES APPLICATIONS Low power, 8-/16-channel, highly integrated multiplexed Process control: PLC/DCS modules analog-to-digital converter (ADC) Voltage, current, temperature, and pressure measurement Integration Flow meters Precision analog input buffers and reference input buffers Medical and scientific multichannel instrumentation 2.5 V precision reference (3.5 ppm/C) Seismic instrumentation Cross point multiplexer (enable system diagnostic) Chemical analysis instrumentation: chromatography 8 full differential or 16 single-ended channels GENERAL DESCRIPTION Clock oscillator Fast settling, highly accurate, low power, 8-/16-channel, GPIO and GPO pins with automatic external mux control multiplexed ADC for low bandwidth input signals with Fast and flexible output rate: 1.25 SPS to 31.25 kSPS integrated input buffers. Channel scan data rate: 6.21 kSPS/channel (161 s settling) Performance specifications Integrated precision, 2.5 V, low drift (3.5 ppm/C), band gap 17.5 noise free bits at 31.25 kSPS reference and integrated oscillator. 24 noise free bits at 1.25 SPS Eight flexible setups with configurability for output data rate, INL: 3 ppm/FSR digital filter mode, offset/gain error correction, reference selection, 85 dB rejection of 50 Hz and 60 Hz with 50 ms settling buffer enables and more. This per channel configurability extends Operates with either 3.3 V or5 V supply to the output data rate used for each channel when using Single supply sinc5 + sinc1 filter. 3.3 V or 5 V AVDD1, 2 V to 5 V AVDD2, and 2 V to 5 V IOVDD Sinc5 + sinc1 filter maximizes channel scan rate, and sinc3 filter Optional split supply maximizes resolution and enhanced 50 Hz/60 Hz rejection, AVDD1 and AVSS 2.5 V or AVDD1 and AVSS 1.65 V Current: 1.4 mA with four selectable options to maximize rejection. 3-/4-wire serial digital interface (Schmitt trigger on SCLK) Integrated diagnostic features, including CRC, register checksum, CRC error checking temperature sensor, crosspoint multiplexer, burnout currents, SPI, QSPI, MICROWIRE, and DSP compatible and GPIOs/GPOs. Package: 40-lead 6 mm 6 mm LFCSP Temperature range: 40C to +105C FUNCTIONAL BLOCK DIAGRAM AVDD1 AVDD2 REGCAPA REF REF+ REFOUT IOVDD REGCAPD BUFFERED 1.8V 1.8V PRECISION LDO LDO REFERENCE REFERENCE CROSSPOINT INPUT MULTIPLEXER BUFFERS INT REF AIN0/REF2 AVDD ANALOG CS INPUT BUFFERS SCLK AIN1/REF2+ SERIAL DIN DIGITAL INTERFACE - ADC FILTER AND CONTROL DOUT/RDY SYNC AIN15 ERROR XTAL AND INTERNAL I/O AND EXTERNAL AVSS CLOCK OSCILLATOR AIN16 MUX CONTROL CIRCUITRY AD7173-8 TEMPERATURE SENSOR AVSS PDSW GPIO0 GPIO1 GPO2 GPO3 XTAL1 XTAL2/CLKIO DGND 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 20132017 Analog Devices, Inc. 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Technical Support www.analog.com 11773-001AD7173-8 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Integrated Functions ...................................................................... 43 Applications ....................................................................................... 1 General-Purpose I/O ................................................................. 43 General Description ......................................................................... 1 External Multiplexer Control ................................................... 43 Functional Block Diagram .............................................................. 1 Delay ............................................................................................ 43 Revision History ............................................................................... 3 16-Bit/24-Bit Conversions......................................................... 43 Specifications ..................................................................................... 4 Serial Interface Reset (DOUT RESET) .................................. 43 Timing Characteristics ................................................................ 8 Synchronization .......................................................................... 43 Absolute Maximum Ratings ............................................................ 9 Error Flags ................................................................................... 44 Thermal Resistance ...................................................................... 9 DATA STAT ............................................................................... 44 ESD Caution .................................................................................. 9 IOSTRENGTH Bit ..................................................................... 44 Pin Configuration and Function Descriptions ........................... 10 Grounding and Layout .................................................................. 45 Typical Performance Characteristics ........................................... 12 Register Summary .......................................................................... 46 Noise Performance and Resolution .............................................. 18 Register Details ............................................................................... 48 Getting Started ................................................................................ 19 Communications Register ......................................................... 48 Power Supplies ............................................................................ 20 Status Register ............................................................................. 50 Digital Communication ............................................................. 20 ADC Mode Register ................................................................... 51 AD7173-8 Reset ........................................................................... 21 Interface Mode Register ............................................................ 52 Configuration Overview ........................................................... 22 Register Check ............................................................................ 53 Circuit Description ......................................................................... 27 Data Register ............................................................................... 53 Analog Input ............................................................................... 27 GPIO Configuration Register ................................................... 54 Reference Options ...................................................................... 29 ID Register................................................................................... 55 Clock Source ............................................................................... 29 Channel Register 0 ..................................................................... 55 Digital Filters ................................................................................... 31 Channel Register 1 to Channel Register 15 ............................ 57 Sinc5 + Sinc1 Filter..................................................................... 31 Setup Configuration Register 0 ................................................ 58 Sinc3 Filter ................................................................................... 32 Setup Configuration Register 1 to Setup Configuration Register 7 ..................................................................................... 59 Single Cycle Settling ................................................................... 33 Filter Configuration Register 0 ................................................. 60 Enhanced 50 Hz and 60 Hz Rejection Filters ......................... 33 Filter Configuration Register 1 to Filter Configuration Operating Modes ............................................................................ 36 Register 7 ..................................................................................... 61 Continuous Conversion Mode ................................................. 36 Offset Register 0 ......................................................................... 62 Continuous Read Mode ............................................................. 37 Offset Register 1 to Offset Register 7 ....................................... 62 Single Conversion Mode ........................................................... 38 Gain Register 0............................................................................ 62 Standby and Power-Down Modes ............................................ 39 Gain Register 1 to Gain Register 7 ........................................... 62 Calibration Modes ...................................................................... 39 Outline Dimensions ....................................................................... 63 Digital Interface .............................................................................. 40 Ordering Guide .......................................................................... 63 Checksum Protection................................................................. 40 CRC Calculation ......................................................................... 41 Rev. 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