Table Of Contents - Analog Devices dBCool ADT7467 Manual

ADT7467

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 ADT7460 and ADT7467 ....................... 9
Recommended Implementation............................................... 10
Serial Bus Interface..................................................................... 11
Write Operations ........................................................................ 12
Read Operations ......................................................................... 13
SMBus Timeout .......................................................................... 13
Voltage Measurement Input...................................................... 13
Analog-to-Digital Converter .................................................... 13
Input Circuitry............................................................................ 14
Voltage Measurement Registers................................................ 14
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
Limits, Status Registers, and Interrupts ....................................... 20
Limit Values................................................................................. 20
Status Registers ........................................................................... 21
THERM Timer............................................................................ 23
REVISION HISTORY
Revision 0: Initial Version
Laying Out 2-Wire and 3-Wire Fans ....................................... 28
Operating from 3.3 V Standby.................................................. 32
XNOR Tree Test Mode .............................................................. 33
Power-On Default ...................................................................... 33
Programming the Automatic Fan Speed Control Loop ............ 34
Automatic Fan Control Overview............................................ 34
Step 1: Hardware Configuration.............................................. 35
Recommended Implementation 1 ........................................... 36
Recommended Implementation 2 ........................................... 37
Step 2: Configuring the MUX................................................... 38
Step 3: T Settings for Thermal Calibration Channels....... 40
MIN
Step 4: PWM
Step 5: PWM
Step 6: T
RANGE
Step 7: T
THERM
Step 8: T for Temperature Channels .................................. 46
HYST
Dynamic T
MIN
Step 9: Operating Points for Temperature Channels ............. 50
Step 10: High and Low Limits for Temperature Channels ... 51
Step 11: Monitoring THERM ................................................... 53
Enhancing System Acoustics .................................................... 54
Step 12: Ramp Rate for Acoustic Enhancement..................... 56
Register Tables ................................................................................ 59
ADT7467 Programming Block Diagram .................................... 77
Outline Dimensions ....................................................................... 78
Ordering Guide .......................................................................... 78
Rev. 0 | Page 2 of 80
for Each PWM (Fan) Output....................... 41
MIN
for PWM (Fan) Outputs.............................. 41
MAX
for Temperature Channels................................ 42
for Temperature Channels ............................... 45
Control Mode ................................................... 48