Datasheet AD7785 (Analog Devices) - 3

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AD7785 TABLE OF CONTENTS
Features .. 1 Offset Register .. 19 Applications... 1 Full-Scale Register.. 19 General Description ... 1 ADC Circuit Information.. 20 Functional Block Diagram .. 1 Overview ... 20 Revision History ... 2 Digital Interface.. 21 Specifications... 3 Circuit Description... 25 Timing Characteristics... 6 Analog Input Channel ... 25 Timing Diagrams.. 7 Instrumentation Amplifier.. 25 Absolute Maximum Ratings.. 8 Bipolar/Unipolar Configuration .. 25 ESD Caution.. 8 Data Output Coding .. 25 Pin Configuration and Function Descriptions... 9 Burnout Currents ... 26 Output Noise and Resolution Specifications .. 11 Excitation Currents .. 26 External Reference.. 11 Bias Voltage Generator .. 26 Internal Reference .. 12 Reference ... 26 Typical Performance Characteristics ... 13 Reset ... 26 On-Chip Registers .. 14 AVDD Monitor ... 27 Communications Register... 14 Calibration... 27 Status Register ... 15 Grounding and Layout .. 27 Mode Register ... 15 Applications Information .. 29 Configuration Register .. 17 Temperature Measurement using a Thermocouple... 29 Data Register ... 18 Temperature Measurement using an RTD.. 30 ID Register... 18 Outline Dimensions ... 31 IO Register... 18 Ordering Guide .. 31
REVISION HISTORY 4/07—Revision 0: Initial Version
Rev. 0 | Page 2 of 32 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS TIMING CHARACTERISTICS TIMING DIAGRAMS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS OUTPUT NOISE AND RESOLUTION SPECIFICATIONS EXTERNAL REFERENCE INTERNAL REFERENCE TYPICAL PERFORMANCE CHARACTERISTICS ON-CHIP REGISTERS COMMUNICATIONS REGISTER RS2, RS1, RS0 = 0, 0, 0 STATUS REGISTER RS2, RS1, RS0 = 0, 0, 0; Power-On/Reset = 0x88 MODE REGISTER RS2, RS1, RS0 = 0, 0, 1; Power-On/Reset = 0x000A CONFIGURATION REGISTER RS2, RS1, RS0 = 0, 1, 0; Power-On/Reset = 0x0710 DATA REGISTER RS2, RS1, RS0 = 0, 1, 1; Power-On/Reset = 0x00000F ID REGISTER RS2, RS1, RS0 = 1, 0, 0; Power-On/Reset = 0xXB IO REGISTER RS2, RS1, RS0 = 1, 0, 1; Power-On/Reset = 0x00 OFFSET REGISTER RS2, RS1, RS0 = 1, 1, 0; Power-On/Reset = 0x800000 FULL-SCALE REGISTER RS2, RS1, RS0 = 1, 1, 1; Power-On/Reset = 0x5XXX00 ADC CIRCUIT INFORMATION OVERVIEW DIGITAL INTERFACE Single Conversion Mode Continuous Conversion Mode Continuous Read CIRCUIT DESCRIPTION ANALOG INPUT CHANNEL INSTRUMENTATION AMPLIFIER BIPOLAR/UNIPOLAR CONFIGURATION DATA OUTPUT CODING BURNOUT CURRENTS EXCITATION CURRENTS BIAS VOLTAGE GENERATOR REFERENCE RESET AVDD MONITOR CALIBRATION GROUNDING AND LAYOUT APPLICATIONS INFORMATION TEMPERATURE MEASUREMENT USING A THERMOCOUPLE TEMPERATURE MEASUREMENT USING AN RTD OUTLINE DIMENSIONS ORDERING GUIDE