Table Of Contents - Analog Devices ADT7473 Manual

ADT7473

TABLE OF CONTENTS

Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 5
Thermal Characteristics .............................................................. 5
ESD Caution.................................................................................. 5
Pin Configuration and Function Descriptions............................. 6
Typical Performance Characteristics ............................................. 7
Product Description......................................................................... 9
Comparison Between ADT7467 and ADT7473 ...................... 9
Recommended Implementation................................................. 9
Serial Bus Interface..................................................................... 10
Write Operations ........................................................................ 11
Read Operations ......................................................................... 12
SMBus Timeout .......................................................................... 12
Voltage Measurement Input...................................................... 12
Analog-to-Digital Converter .................................................... 12
Input Circuitry............................................................................ 12
Voltage Measurement Registers................................................ 12
V Limit Registers ................................................................... 13
CCP
Additional ADC Functions for Voltage Measurements ........ 13
Temperature Measurement Method ........................................ 14
Series Resistance Cancellation.................................................. 16
Factors Affecting Diode Accuracy ........................................... 16
Additional ADC Functions for Temperature Measurement 18
Limits, Status Registers, and Interrupts....................................... 19
Limit Values................................................................................. 19
Status Registers ........................................................................... 20
REVISION HISTORY
6/05-Revision 0: Initial Version
THERM Timer ........................................................................... 22
Fan Drive Using PWM Control ............................................... 25
Fan Presence Detect................................................................... 30
Sleep States .................................................................................. 30
XNOR Tree Test Mode .............................................................. 31
Power-On Default ...................................................................... 31
Programming the Automatic Fan Speed Control Loop ............ 32
Automatic Fan Control Overview............................................ 32
Step 1: Hardware Configuration .............................................. 33
Step 2: Configuring the Mux .................................................... 35
Step 3: T Settings for Thermal Calibration Channels ...... 37
MIN
Step 4: PWM
Step 5: PWM
Step 6: T
RANGE
Step 7: T
THERM
Step 8: T for Temperature Channels.................................. 43
HYST
Dynamic T
MIN
Step 9: Operating Points for Temperature Channels............. 47
Step 10: High and Low Limits for Temperature Channels ... 48
Step 11: Monitoring THERM ................................................... 50
Enhancing System Acoustics .................................................... 51
Step 12: Ramp Rate for Acoustic Enhancement..................... 53
Register Tables ................................................................................ 56
Outline Dimensions ....................................................................... 74
Ordering Guide .......................................................................... 74
Rev. 0 | Page 2 of 76
for Each PWM (Fan) Output ...................... 38
MIN
for PWM (Fan) Outputs.............................. 38
MAX
for Temperature Channels................................ 39
for Temperature Channels ............................... 42
Control Mode ................................................... 45