Datasheet AD7798, AD7799 (Analog Devices) - 2

link to page 1 link to page 1 link to page 1 link to page 1 link to page 1 link to page 2 link to page 3 link to page 6 link to page 8 link to page 8 link to page 9 link to page 10 link to page 10 link to page 11 link to page 12 link to page 13 link to page 13 link to page 14 link to page 14 link to page 16 link to page 17 link to page 17 link to page 17 link to page 17 link to page 17 link to page 18 link to page 18 link to page 19 link to page 22 link to page 22 link to page 22 link to page 22 link to page 23 link to page 23 link to page 23 link to page 23 link to page 23 link to page 24 link to page 24 link to page 25 link to page 26 link to page 26 link to page 27 link to page 27
AD7798/AD7799 Data Sheet TABLE OF CONTENTS
Features .. 1 IO Register... 17 Interface ... 1 Offset Register .. 17 Applications ... 1 Ful -Scale Register .. 17 Functional Block Diagram .. 1 ADC Circuit Information.. 18 General Description ... 1 Overview ... 18 Revision History ... 2 Digital Interface .. 19 Specifications ... 3 Circuit Description... 22 Timing Characteristics ... 6 Analog Input Channel ... 22 Absolute Maximum Ratings .. 8 Instrumentation Amplifier.. 22 ESD Caution .. 8 Bipolar/Unipolar Configuration .. 22 Pin Configuration and Function Descriptions ... 9 Data Output Coding .. 23 Output Noise and Resolution Specifications .. 10 Burnout Currents ... 23 AD7798 .. 10 Reference ... 23 AD7799 .. 11 Reference Detect ... 23 Typical Performance Characteristics ... 12 Reset ... 23 On-Chip Registers .. 13 AVDD Monitor ... 24 Communication Register .. 13 Calibration... 24 Status Register ... 14 Grounding and Layout .. 25 Mode Register ... 14 Applications Information .. 26 Configuration Register .. 16 Weigh Scales .. 26 Data Register ... 17 Outline Dimensions ... 27 ID Register ... 17 Ordering Guide .. 27
REVISION HISTORY 7/13—Rev. A to Rev. B
Changes to Table 3 .. 8 Changes to Digital Interface Section .. 19 Changes to Ordering Guide .. 27
3/07—Rev. 0 to Rev. A
Updated Format .. Universal Changes to Specifications .. 3 Changes to Table 5 and Table 6 ... 10 Changes to Table 7 and Table 8 ... 11 Changes to Table 14 .. 15 Changes to Ordering Guide .. 27
1/05—Revision 0: Initial Version
Rev. B | Page 2 of 28 Document Outline Features Interface Applications Functional Block Diagram General Description Revision History Specifications Timing Characteristics Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Output Noise and Resolution Specifications AD7798 AD7799 Typical Performance Characteristics On-Chip Registers Communication Register RS2, RS1, RS0 = 0, 0, 0 Status Register RS2, RS1, RS0 = 0, 0, 0; Power-On/Reset = 0x80 (AD7798)/0x88 (AD7799) 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 = 0x0000(00) ID Register RS2, RS1, RS0 = 1, 0, 0; Power-On/Reset = 0xX8 (AD7798)/0xX9 (AD7799) IO Register RS2, RS1, RS0 = 1, 0, 1; Power-On/Reset = 0x00 Offset Register RS2, RS1, RS0 = 1, 1, 0; Power-On/Reset = 0x8000(AD7798)/0x800000 (AD7799) Full-Scale Register RS2, RS1, RS0 = 1, 1, 1; Power-On/Reset = 0x5XXX (AD7798)/0x5XXX00 (AD7799) 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 Reference Reference Detect Reset AVDD Monitor Calibration Grounding and Layout Applications Information Weigh Scales Outline Dimensions Ordering Guide