ADT7467 Analog Devices, Inc., ADT7467 Datasheet - Page 48

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

ADT7467
STEP 8: T
T
temperature measured drops below T
off. The premise for temperature hysteresis (T
without it the fan would merely chatter or cycle on and off
repeatedly whenever temperature hovered near the T
The T
system to cool down or heat up as the fan turns on and off.
Values of hysteresis are programmable in the range 1°C to 15°C.
Larger values of T
off. The T
The T
for fan on/off, but also is used for the T
described in Step 6. Therefore, programming Registers 0x6D
and 0x6E sets the hysteresis for both fan on/off and the THERM
function.
HYST
is the amount of extra cooling a fan provides after the
HYST
HYST
HYST
value determines the amount of time needed for the
setting not only applies to the temperature hysteresis
HYST
default value is set at 4°C.
FOR TEMPERATURE CHANNELS
HYST
prevent the fans from chattering on and
AMBIENT TEMP
REMOTE 2 =
REMOTE 1 =
VRM TEMP
CPU TEMP
LOCAL =
100%
0%
THERMAL CALIBRATION
THERMAL CALIBRATION
THERMAL CALIBRATION
MIN
T
T
T
T
MIN
THERM
MIN
MIN
MIN
before the fan turns
hysteresis value, as
HYST
Figure 67. How T
T
RANGE
T
T
T
RANGE
RANGE
RANGE
) is that
T
100%
100%
100%
THERM
MIN
0%
0%
0%
setting.
MUX
THERM
Rev. A | Page 48 of 80
Relates to Automatic Fan Control
PWM
PWM
PWM
MIN
MIN
MIN
Hysteresis Registers
Reg. 0x6D, Remote 1, local hysteresis register
<7:4>, Remote 1 temperature hysteresis (4°C default)
<3:0>, local temperature hysteresis (4°C default)
Reg. 0x6E, Remote 2 temp hysteresis register
<7:4>, Remote 2 temperature hysteresis (4°C default)
In some applications, it is required that fans continue to run at
PWM
below T
(Reg. 0x62) allow the fans to be either turned off or kept
spinning below T
has no effect on the fan when the temperature drops below T
ENHANCEMENT)
ENHANCEMENT)
TACHOMETER 1
MEASUREMENT
TACHOMETER 2
MEASUREMENT
ENHANCEMENT)
TACHOMETER 3
MEASUREMENT
(ACOUSTIC
(ACOUSTIC
(ACOUSTIC
CONTROL
CONTROL
CONTROL
RAMP
RAMP
AND 4
RAMP
MIN
MIN
, instead of turning off when the temperature drops
. Bits <7:5> of Enhanced Acoustics Register 1
GENERATOR
GENERATOR
GENERATOR
CONFIG
CONFIG
CONFIG
MIN
PWM
PWM
PWM
PWM
PWM
PWM
. If the fans are always on, the T
PWM1
TACH1
PWM2
TACH2
PWM3
TACH3
FRONT CHASSIS
REAR CHASSIS
CPU FAN SINK
HYST
value
MIN
.