ADT7467 Analog Devices, Inc., ADT7467 Datasheet - Page 42

• Manufacturer Part Number: ADT7467
• Description: Dbcool Remote Thermal Monitor And Fan Controller
• Manufacturer: Analog Devices, Inc.

ADT7467
STEP 3: T
CALIBRATION CHANNELS
T
using automatic fan control mode. The speed at which the fan
runs at T
temperature-channel specific, for example, 25°C for ambient
channel, 30°C for VRM temperature, and 40°C for processor
temperature.
T
can be programmed in 1°C increments. There is a T
associated with each temperature measurement channel:
Remote 1, local, and Remote 2 temperature. Once the T
value is exceeded, the fan turns on and runs at the minimum
PWM duty cycle. The fan turns off once the temperature has
dropped below T
To overcome fan inertia, the fan spins up until two valid TACH
rising edges are counted. See the Fan Start-Up Timeout section
for more details. In some cases, primarily for psychoacoustic
reasons, it is desirable that the fan never switch off below T
When set, Bits <7:5> of the Enhanced Acoustics Register 1
(Reg. 0x62) keep the fans running at the PWM minimum duty
cycle if the temperature falls below T
MIN
MIN
is the temperature at which the fans start to turn on when
is an 8-bit value, either twos complement or Offset 64, that
MIN
MIN
is programmed later. The T
SETTINGS FOR THERMAL
MIN
AMBIENT TEMP
– T
REMOTE 2 =
REMOTE 1 =
VRM TEMP
CPU TEMP
HYST
LOCAL =
100%
0%
.
THERMAL CALIBRATION
THERMAL CALIBRATION
THERMAL CALIBRATION
T
T
T
T
MIN
MIN
MIN
MIN
MIN
.
MIN
values chosen are
T
T
T
RANGE
RANGE
RANGE
100%
100%
100%
Figure 57. Understanding the T
0%
0%
0%
MIN
register
MIN
MUX
MIN
Rev. A | Page 42 of 80
.
PWM
PWM
PWM
MIN
MIN
MIN
T
Reg. 0x67, Remote 1 temperature T
Reg. 0x68, local temperature T
Reg. 0x69, Remote 2 temperature T
Enhance Acoustics Register 1 (Reg. 0x62)
Bit 7 (MIN3) = 0, PWM3 is off (0% PWM duty cycle) when the
temperature is below T
Bit 7 (MIN3) = 1, PWM3 runs at PWM3 minimum duty cycle
when the temperature is below T
Bit 6 (MIN2) = 0, PWM2 is off (0% PWM duty cycle) when the
temperature is below T
Bit 6 (MIN2) = 1, PWM2 runs at PWM2 minimum duty cycle
when the temperature is below T
Bit 5 (MIN1) = 0, PWM1 is off (0% PWM duty cycle) when the
temperature is below T
Bit 5 (MIN1) = 1, PWM1 runs at PWM1 minimum duty cycle
when the temperature is below T
MIN
MIN
ENHANCEMENT)
ENHANCEMENT)
ENHANCEMENT)
TACHOMETER 1
MEASUREMENT
TACHOMETER 2
MEASUREMENT
TACHOMETER 3
MEASUREMENT
Registers
(ACOUSTIC
(ACOUSTIC
(ACOUSTIC
Parameter
CONTROL
CONTROL
CONTROL
RAMP
RAMP
AND 4
RAMP
GENERATOR
GENERATOR
GENERATOR
CONFIG
CONFIG
CONFIG
PWM
PWM
PWM
PWM
PWM
PWM
MIN
MIN
MIN
– T
– T
– T
HYST
HYST
HYST
MIN
PWM1
TACH1
PWM2
TACH2
PWM3
TACH3
MIN
MIN
MIN
.
.
.
= 0x9A (90°C)
MIN
MIN
FRONT CHASSIS
REAR CHASSIS
– T
– T
– T
CPU FAN SINK
= 0x9A (90°C)
= 0x9A (90°C)
HYST
HYST
HYST
.
.
.