ADT7468 Analog Devices, Inc., ADT7468 Datasheet - Page 52

• Manufacturer Part Number: ADT7468
• Description: Dbcool Remote Thermal Controller And Voltage Monitor
• Manufacturer: Analog Devices, Inc.

ADT7468
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
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
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
below T
STEP 9: OPERATING POINTS FOR TEMPERATURE
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
MIN
MIN
MIN
− T
− T
− T
HYST
HYST
HYST
.
.
.
MIN
MIN
MIN
AMBIENT TEMP
− T
− T
− T
REMOTE 2 =
REMOTE 1 =
VRM TEMP
CPU TEMP
LOCAL =
100%
HYST
HYST
HYST
0%
.
.
.
Figure 69. The T
THERMAL CALIBRATION
THERMAL CALIBRATION
THERMAL CALIBRATION
T
T
T
T
MIN
MIN
MIN
MIN
T
RANGE
T
T
T
HYST
RANGE
RANGE
RANGE
Value Applies to Fan On/Off Hysteresis and THERM Hysteresis
T
100%
100%
100%
THERM
0%
0%
0%
MUX
Rev. A | Page 52 of 84
PWM
PWM
PWM
MIN
MIN
MIN
required to run as fast. The ADT7468 increases or decreases fan
speeds as necessary to maintain the operating point
temperature, allowing for system-to-system variation and
removing the need for worst-case design. If a sensible operating
point value is chosen, any T
system characterization. If the T
sooner than required, and the temperature is below the operat-
ing point. In response, the ADT7468 increases T
fans off longer and to allow the temperature zone to get closer
to the operating point. Likewise, too high a T
the operating point to be exceeded, and in turn, the ADT7468
reduces T
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
Reg. 0x33, Remote 1 operating point = 0xA4 (100°C default)
Reg. 0x34, local operating point = 0xA4 (100°C default)
Reg. 0x35, Remote 2 operating point = 0xA4 (100°C default)
ENHANCEMENT)
ENHANCEMENT)
TACHOMETER 1
MEASUREMENT
TACHOMETER 2
MEASUREMENT
ENHANCEMENT)
TACHOMETER 3
MEASUREMENT
(ACOUSTIC
(ACOUSTIC
(ACOUSTIC
CONTROL
CONTROL
CONTROL
RAMP
RAMP
AND 4
RAMP
MIN
to turn the fans on sooner to cool the system.
GENERATOR
GENERATOR
GENERATOR
CONFIG
CONFIG
CONFIG
PWM
PWM
PWM
PWM
PWM
PWM
PWM1
TACH1
PWM2
TACH2
PWM3
TACH3
MIN
value can be selected in the
FRONT CHASSIS
REAR CHASSIS
CPU FAN SINK
MIN
value is too low, the fans run
MIN
MIN
value causes
to keep the