Table Of Contents - Analog Devices dBCool ADT7473 Manual

ADT7473
T ABLE OF CONTENTS
Fe atures .............................................................................................. 1
G eneral Description ......................................................................... 1
Functional Block Diagram .............................................................. 1
Sp ecifications..................................................................................... 4
Timing Diagram ........................................................................... 5
Ab solute Maximum Ratings............................................................ 6
Thermal Resistance ...................................................................... 6
ESD Caution.................................................................................. 6
Pi n Configuration and Function Descriptions............................. 7
Ty pical Performance Characteristics ............................................. 8
Product Description....................................................................... 10
Comparison Between ADT7467 and ADT7473 .................... 10
How to Set the Functionality of Pin 9...................................... 10
Recommended Implementation............................................... 10
Serial Bus Interface..................................................................... 11
Write Operations ........................................................................ 12
Read Operations ......................................................................... 13
SMBus Timeout .......................................................................... 13
Voltage Measurement I nput...................................................... 13
Analog-to-Digital Converter .................................................... 13
Input Circuitry.........................................................
Voltage Measurement Registers................................................ 13
V Limit Registers ................................................................... 14
CCP
Additional ADC Functions for Voltage Measurements ........ 14
Temperature Measurement Method ........................................ 15
Series Resistance Cancellation.................................................. 17
Factors Affecting Diode Accuracy ........................................... 17
Additional ADC Functions for Temperature Measurement 19
Li mits, Status Registers, and Interrupts....................................... 20
Limit Values ................................................................................ 20
Interrupt Status Registers .......................................................... 21
THERM Timer ........................................................................... 23
Fan Presence Detect................................................................... 31
Sleep States .................................................................................. 31
XNOR Tree Test Mode .............................................................. 31
Power-On Default ...................................................................... 31
Pr ogramming the Automatic Fan Speed Control Loop ............ 33
Automatic Fan Control Overview............................................ 33
Step 1: Hardware Configuration .............................................. 34
Step 2: Configuring the Mux .................................................... 36
Step 3: T
Step 4: PWM
Step 5: PWM
Step 6: T
Step 7: T
Step 8: T
Dynamic T
Step 9: Operating Points for Temperature Channels............. 49
................... 13
Step 10: High and Low Limits for Temperature Channels ... 50
Step 11: Monitoring THERM
Enhancing System Acoustics .................................................... 53
Step 12: Ramp Rate for Acoustic Enhancement..................... 55
Register Tables ................................................................................ 58
Outline Dimensions ....................................................................... 76
Ordering Guide .......................................................................... 76
Rev. A | Page 2 of 76
Settings for Thermal Calibration Channels
MIN
for Each PWM (Fan) Output ...................... 40
MIN
for PWM (Fan) Outputs.............................. 40
MAX
for Temperature Channels................................ 41
RANGE
for Temperature Channels ............................... 44
THERM
for Temperature Channels.................................. 45
HYST
Control Mode ................................................... 47
MIN
................................................... 52
...... 38