ADT7476 Analog Devices, Inc., ADT7476 Datasheet - Page 38

• Manufacturer Part Number: ADT7476
• Description: Dbcool Remote Thermal Controller And Voltage Monitor
• Manufacturer: Analog Devices, Inc.

ADT7476
STEP 1: HARDWARE CONFIGURATION
During system design, the motherboard sensing and control
capabilities should be addressed early in the design stages.
Decisions about how these capabilities are used should involve
the system thermal/mechanical engineer. Ask the following
questions:
•
•
•
•
The ADT7476 offers multifunction pins that can be recon-
figured to suit different system requirements and physical
layouts. These multifunction pins are software programmable.
What ADT7476 functionality is used?
• TACH4 fan speed measurement or overtemperature
PWM2 or SMBALERT ?
THERM function?
2.5 V voltage monitoring or overtemperature THERM
function?
12 V voltage monitoring or VID5 input?
REMOTE 1
REMOTE 2
LOCAL
TEMP
TEMP
TEMP
THERMAL CALIBRATION
THERMAL CALIBRATION
THERMAL CALIBRATION
T
T
T
MIN
MIN
MIN
T
T
T
RANGE
RANGE
RANGE
Figure 47. Automatic Fan Control Block Diagram
100%
100%
100%
0%
0%
0%
MUX
Rev. B | Page 38 of 72
PWM
PWM
PWM
MIN
MIN
MIN
CONFIG
CONFIG
CONFIG
•
•
•
TACHOMETER 1
MEASUREMENT
TACHOMETER 2
MEASUREMENT
TACHOMETER 3
MEASUREMENT
PWM
PWM
PWM
GENERATOR
GENERATOR
GENERATOR
AND 4
This influences the assignment of the temperature
measurement channels to particular system thermal
zones. For example, locating the ADT7476 close to the
VRM controller circuitry allows the VRM temperature
to be monitored using the local temperature channel.
PWM
PWM
PWM
How many fans are supported in the system, three or
four? This influences the choice of whether to use the
TACH4 pin or to reconfigure it for the THERM
function.
Is the CPU fan to be controlled using the ADT7476,
or will the CPU fan run at full speed 100% of the
time? Running at 100% frees up a PWM output, but
the system is louder.
Where will the ADT7476 be physically located in the
system?
ENHANCEMENT)
ENHANCEMENT)
ENHANCEMENT)
(ACOUSTIC
(ACOUSTIC
(ACOUSTIC
CONTROL
CONTROL
CONTROL
RAMP
RAMP
RAMP
PWM1
TACH1
PWM2
TACH2
PWM3
TACH3