Datasheet
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
I
2
C 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
V
DRIVE
............................................................................................ 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
T
SENSE
Conversion Result Register (0x02) ................................ 18
T
SENSE
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
I
2
C Interface .................................................................................... 21
Serial Bus Address Byte ............................................................. 21
General I
2
C 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