Datasheet

6-Channel Intelligent Fan Controller
MAX31785
2
TABLE OF CONTENTS
Absolute Maximum Ratings ...................................................................... 6
Recommended Operating Conditions
.............................................................. 6
DC Electrical Characteristics
..................................................................... 6
I
2
C/SMBus Interface Electrical Characteristics ....................................................... 8
I
2
C/SMBus Timing ............................................................................. 8
Typical Operating Characteristics
................................................................. 9
Pin Configuration
............................................................................. 10
Pin Description
............................................................................... 10
Block Diagram
............................................................................... 12
Multiple Device Connection Diagram
.............................................................. 13
Detailed Description
........................................................................... 14
Address Select
.............................................................................16
SMBus/PMBus Operation
.....................................................................16
SMBus/PMBus Communication Examples
.....................................................16
Group Command
...........................................................................17
Group Command Write Format
..............................................................17
Addressing
................................................................................17
ALERT and Alert Response Address (ARA)
.......................................................17
Alert Response Address (ARA) Byte Format
....................................................18
Host Sends or Reads Too Few Bits
.............................................................18
Host Sends or Reads Too Few Bytes
............................................................18
Host Sends Too Many Bytes or Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Host Reads Too Many Bytes or Bits
.............................................................18
Host Sends Improperly Set Read Bit in the Slave Address Byte
.......................................18
Unsupported Command Code Received
.........................................................18
Invalid Data Received
........................................................................18
Host Reads from a Write-Only Command
........................................................19
Host Writes to a Read-Only Command
...........................................................19
SMBus Timeout
.............................................................................19
PMBus Operation
...........................................................................19
PMBus Protocol Support
......................................................................19
Data Format
................................................................................19
Interpreting Received DIRECT Format Values
.....................................................20
Sending a DIRECT Format Value
...............................................................20
Fault Management and Reporting
..............................................................21
System Watchdog Timer
......................................................................21
Temperature Sensor Operation
.................................................................21