link to page 1 link to page 1 link to page 1 link to page 1 link to page 3 link to page 4 link to page 6 link to page 7 link to page 7 link to page 7 link to page 8 link to page 9 link to page 12 link to page 13 link to page 13 link to page 13 link to page 14 link to page 14 link to page 14 link to page 15 link to page 15 link to page 15 link to page 16 link to page 16 link to page 18 link to page 19 link to page 19 link to page 20 link to page 20 link to page 21 link to page 21 link to page 21 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 24 link to page 24 link to page 25 link to page 25 link to page 27 link to page 28 link to page 28 AD7291Data SheetTABLE OF CONTENTS Features .. 1 Address Pointer Register ... 15 Functional Block Diagram .. 1 Command Register (0x00) .. 17 General Description ... 1 Voltage Conversion Result Register (0x01) .. 18 Product Highlights ... 1 TSENSE Conversion Result Register (0x02) .. 18 Revision History ... 2 TSENSE Average Result Register (0x03) .. 19 Specifications ... 3 Limit Registers (0x04 to 0x1E) ... 19 I2C Timing Specifications .. 5 Hysteresis Register ... 20 Absolute Maximum Ratings .. 6 Alert Status Register A and Alert Status Register B (0x1F and Thermal Resistance .. 6 0x20) ... 20 ESD Caution .. 6 I2C Interface .. 21 Pin Configuration and Function Descriptions ... 7 Serial Bus Address Byte ... 21 Typical Performance Characteristics ... 8 General I2C Timing .. 21 Terminology .. 11 Writing to the AD7291 .. 22 Circuit Information .. 12 Writing Two Bytes of Data to a 16-Bit Register ... 22 Converter Operation .. 12 Writing to Multiple Registers .. 22 Analog Input ... 12 Reading Data From the AD7291 .. 23 ADC Transfer Function ... 13 Reading Two Bytes of Data from a 16-Bit Register ... 23 Temperature Sensor Operation .. 13 Modes of Operation ... 24 Temperature Sensor Averaging ... 13 Command Mode .. 24 V Autocycle Mode .. 26 DRIVE .. 14 The Internal or External Reference .. 14 Outline Dimensions ... 27 Reset ... 14 Ordering Guide .. 27 Internal Register Structure .. 15 REVISION HISTORY10/2016—Rev. B to Rev. C Changes to Command Mode Section .. 25 10/2011—Rev. A to Rev. B Changes to Table 9 .. 16 8/2011—Rev. 0 to Rev. A Changes to Temperature Sensor—Internal, Accuracy Parameter, Table 2 .. 3 1/2011—Revision 0: Initial Version Rev. C | Page 2 of 28 Document Outline FEATURES FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION PRODUCT HIGHLIGHTS REVISION HISTORY SPECIFICATIONS I2C TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY CIRCUIT INFORMATION CONVERTER OPERATION ANALOG INPUT ADC TRANSFER FUNCTION TEMPERATURE SENSOR OPERATION TEMPERATURE SENSOR AVERAGING Temperature Value Format VDRIVE THE INTERNAL OR EXTERNAL REFERENCE RESET INTERNAL REGISTER STRUCTURE ADDRESS POINTER REGISTER COMMAND REGISTER (0x00) Sample Delay and Bit Trial Delay VOLTAGE CONVERSION RESULT REGISTER (0x01) Temperature Value Format TSENSE CONVERSION RESULT REGISTER (0x02) TSENSE AVERAGE RESULT REGISTER (0X03) LIMIT REGISTERS (0X04 TO 0X1E) DATAHIGH Register DATALOW Register HYSTERESIS REGISTER ALERT STATUS REGISTER A AND ALERT STATUS REGISTER B (0x1F AND 0x20) I2C INTERFACE SERIAL BUS ADDRESS BYTE GENERAL I2C TIMING WRITING TO THE AD7291 WRITING TWO BYTES OF DATA TO A 16-BIT REGISTER WRITING TO MULTIPLE REGISTERS READING DATA FROM THE AD7291 READING TWO BYTES OF DATA FROM A 16-BIT REGISTER MODES OF OPERATION COMMAND MODE AUTOCYCLE MODE OUTLINE DIMENSIONS ORDERING GUIDE