AD7291

Data Sheet

Rev. C | Page 2 of 28

TABLE OF CONTENTS

Features .............................................................................................. 1

 

Functional Block Diagram .............................................................. 1

 

General Description ......................................................................... 1

 

Product Highlights ........................................................................... 1

 

Revision History ............................................................................... 2

 

Specifications..................................................................................... 3

 

I2C Timing Specifications............................................................ 5

 

Absolute Maximum Ratings............................................................ 6

 

Thermal Resistance ...................................................................... 6

 

ESD Caution.................................................................................. 6

 

Pin Configuration and Function Descriptions............................. 7

 

Typical Performance Characteristics ............................................. 8

 

Terminology .................................................................................... 11

 

Circuit Information ........................................................................ 12

 

Converter Operation.................................................................. 12

 

Analog Input ............................................................................... 12

 

ADC Transfer Function............................................................. 13

 

Temperature Sensor Operation ................................................ 13

 

Temperature Sensor Averaging................................................. 13

 

VDRIVE ............................................................................................ 14

 

The Internal or External Reference.......................................... 14

 

Reset ............................................................................................. 14

 

Internal Register Structure ............................................................ 15

 

Address Pointer Register ........................................................... 15

 

Command Register (0x00)........................................................ 17

 

Voltage Conversion Result Register (0x01) ............................ 18

 

TSENSE Conversion Result Register (0x02)................................ 18

 

TSENSE Average Result Register (0x03) ...................................... 19

 

Limit Registers (0x04 to 0x1E) ................................................. 19

 

Hysteresis Register ..................................................................... 20

 

Alert Status Register A and Alert Status Register B (0x1F and

0x20)............................................................................................. 20

 

I2C Interface .................................................................................... 21

 

Serial Bus Address Byte ............................................................. 21

 

General I2C Timing.................................................................... 21

 

Writing to the AD7291 .................................................................. 22

 

Writing Two Bytes of Data to a 16-Bit Register ..................... 22

 

Writing to Multiple Registers.................................................... 22

 

Reading Data From the AD7291.................................................. 23

 

Reading Two Bytes of Data from a 16-Bit Register ............... 23

 

Modes of Operation ....................................................................... 24

 

Command Mode ........................................................................ 24

 

Autocycle Mode.......................................................................... 26

 

Outline Dimensions ....................................................................... 27

 

Ordering Guide .......................................................................... 27

 

REVISION HISTORY

10/2016—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