ADT7473 Analog Devices, Inc., ADT7473 Datasheet - Page 49

• Manufacturer Part Number: ADT7473
• Description: Dbcool Remote Thermal Monitor And Fan Controller
• Manufacturer: Analog Devices, Inc.

STEP 9: OPERATING POINTS FOR TEMPERAT
CHANNELS
The operating point for each temperature channel is the optimal
temperature for that thermal zone. The hotter each zone is
allowed to be, the quieter the system, because the fans are not
required to run as fast. The ADT7473 in eases or decreas
speeds as necessary to maintain the operating point temp
tur , allowing for system-to-system variation and removing the
need
chos
terization. If the T
req ired, and the temperature is below the operating poin
resp
longer and to allow the temperature zone to get closer to the
operating point. Likewise, too high a T
operating point to be exceeded, and in turn, the ADT7473
reduces T
e
u
onse, the ADT7473 increases T
en, any T
for worst-case design. If a sensible operating point value i
MIN
to turn the fans on sooner to cool the system.
MIN
value can be selected in the system charac-
MIN
AMBIENT TEMP
value is too low, the fans run sooner than
REMOTE 2 =
REMOTE 1 =
VRM TEMP
CPU TEMP
LOCAL =
THERMAL CALIBRATION
THERMAL CALIBRATION
THERMAL CALIBRATION
Figure 64. Operating Point Value Dynamically Ad
MIN
T
T
T
MIN
MIN
MIN
MIN
to keep the
cr
value causes the
T
T
T
RANGE
RANGE
RANGE
fans off
100%
100%
100%
0%
0%
0%
URE
era-
t. In
es fan
MUX
Rev. A | Page 49 of 76
OPERATING
s
POINT
PW
PW
PW
MI
MI
MI
N
N
N
M
M
Programming Operating Point Registers
There are three operating point registers, one for each
temperature channel. These 8-bit registers allow the operating
point temperatures to be programmed with 1°C resolution.
Operating Point Registers
Register 0x33, Remote 1 Operating Point = 0xA4
(100°C default)
Register 0x34, Local Operating Point = 0xA4 (100°C d
Register 0x35, Remote 2 Operating Point = 0xA4
(100°C default)
M
jus Automatic Fan Control Settings
ts
ENHANCEMENT)
ENHANCEMENT)
ENHANCEMENT)
TACHOMETER 1
MEASUREMENT
TACHOMETER 2
MEASUREMENT
TACHOMETER 3
MEASUREMENT
(ACOUSTIC
(ACOUSTIC
(ACOUSTIC
CONTROL
CONTROL
CONTROL
RAMP
RAMP
AND 4
RAMP
GENERATOR
GENERATOR
GENERATOR
CONFIG
CONFIG
CONFIG
PWM
PWM
PWM
PWM
PWM
PWM
PWM1
TACH1
PWM2
TACH2
PWM3
TACH3
FRONT CHASSIS
REAR CHASSIS
CPU FAN SINK
ADT7473
efault)