8-Channel DAS with 18-Bit, 1 MSPS Bipolar Input, Simultaneous Sampling ADC Data Sheet AD7606C-18 FEATURES CALIBRATION AND DIAGNOSTICS 18-bit ADC with 1 MSPS on all channels Per channel system phase, offset, and gain calibration Input buffer with 1 M minimum analog input impedance (R ) Analog input open circuit detection feature IN Single 5 V analog supply and 1.71 V to 5.25 V V Self diagnostics and monitoring features DRIVE Per channel selectable analog input ranges CRC error checking on read and write data and registers Bipolar single-ended: 12.5 V, 10 V, 6.25 V, 5 V, 2.5 V APPLICATIONS Unipolar single-ended: 0 V to 12.5 V, 0 V to 10 V, 0 V to 5 V Power line monitoring Bipolar differential: 20 V, 12.5 V, 10 V, 5 V Protective relays Two bandwidth options: 25 kHz and 220 kHz, per channel Multiphase motor control Flexible digital filter, oversampling ratio up to 256 Instrumentation and control systems 40C to +125C operating range Data acquisition systems 21 V input clamp protection with 6 kV ESD Pin to pin compatible to the AD7606B, AD7608, and AD7609 COMPANION PRODUCTS Performance Voltage References: ADR4525, LT6657, LTC6655 93 dB typical SNR for 20 V bipolar differential range Digital Isolators: ADuM142E, ADuM6422A, ADuM5020, 102 dB SNR, oversampling by 32 ADuM5028 100 dB typical THD for all other ranges AD7606x Family Software Model TUE = 0.05% of FSR maximum, external reference Additional companion products on the AD7606C-18 product 0.5 ppm/ C typical PFS and NFS error drift page 3 ppm/ C typical reference temperature coefficient FUNCTIONAL BLOCK DIAGRAM 5V 5V 1.71V TO 5.25V 100nF 100nF 1F 100nF 1F V AV REGCAP AV REGCAP CC CC DRIVE ALDO DLDO 1M V1+ CLAMP CONVST CLK OSC PGA 1M SAR V1 RESET CLAMP LPF RANGE CONTROL INPUTS OS0 TO OS2 1M V8+ BUSY CLAMP PROGRAMMABLE PGA 1M SAR FRSTDATA V8 DIGITAL FILTER CLAMP LPF OPTIONAL SERIAL D A TO D H OUT OUT RC FILTER ADC, PGA, AND SDI CHANNEL REFCAPA SCLK CONFIGURATION PARALLEL/ 10F + SERIAL CS INTERFACE OPTIONAL EXTERNAL PARALLEL DB0 TO DB17 REFCAPB GAIN, OFFSET REFERENCE AND PHASE AV CC RD CALIBRATION INTERNAL REFIN/REFOUT +2.5V REFERENCE WR V V IN OUT + 100nF 2.5V DIAGNOSTICS PAR/SER SEL ADR4525 1F 0.1F REF AND SENSOR REFSELECT DISCONNECT GND REFGND AD7606C-18 AGND Figure 1. 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Trademarks and registered trademarks are the property of their respective owners. 24593-001AD7606C-18 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Padding Oversampling .............................................................. 37 Calibration and Diagnostics ........................................................... 1 External Oversampling Clock .................................................. 37 Applications ...................................................................................... 1 System Calibration Features ......................................................... 38 Companion Products ....................................................................... 1 System Phase Calibration .......................................................... 38 Functional Block Diagram .............................................................. 1 System Gain Calibration ........................................................... 38 Revision History ............................................................................... 2 System Offset Calibration ......................................................... 39 General Description ......................................................................... 3 Analog Input Open Circuit Detection .................................... 39 Specifications .................................................................................... 4 Digital Interface .............................................................................. 41 Timing Specifications .................................................................. 7 Parallel Interface ......................................................................... 42 Absolute Maximum Ratings ......................................................... 11 Serial Interface ............................................................................ 45 Thermal Resistance .................................................................... 11 Diagnostics ...................................................................................... 50 Electrostatic Discharge (ESD) Ratings .................................... 11 Reset Detection ........................................................................... 50 ESD Caution................................................................................ 11 Digital Error ................................................................................ 50 Pin Configuration and Function Descriptions .......................... 12 Diagnostics Multiplexer ............................................................ 53 Typical Performance Characteristics ........................................... 16 Typical Connection Diagram ....................................................... 54 Terminology .................................................................................... 27 Applications Information ............................................................. 56 Theory of Operation ...................................................................... 29 Layout Guidelines ...................................................................... 56 Analog Front-End ...................................................................... 29 Register Summary .......................................................................... 58 SAR ADC ..................................................................................... 30 Register Details ............................................................................... 59 Reference ..................................................................................... 32 Outline Dimensions ....................................................................... 75 Operation Modes ........................................................................ 32 Ordering Guide .......................................................................... 75 Digital Filter .................................................................................... 35 REVISION HISTORY 4/2021Rev. 0 to Rev. A Changes to Table 19 ....................................................................... 36 Changes to Features Section ........................................................... 1 Change to System Gain Calibration Section .............................. 38 Change to Table 1 ............................................................................. 3 Added Figure 94 Renumbered Sequentially .............................. 38 Changes to Specifications Section and Table 2 ............................ 4 Change to Table 23 ........................................................................ 41 Change to Table 3 ............................................................................. 7 Change to Figure 106 ..................................................................... 45 Changes to Figure 45 and Figure 46 ............................................ 22 Changes to Temperature Sensor Section .................................... 53 Changes to Figure 58, Figure 59, and Figure 62 ......................... 24 Changes to Figure 78 and Figure 80 ............................................ 30 10/2020Revision 0: Initial Version Changes to Table 18 ....................................................................... 35 Rev. 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