ADT7475 Analog Devices, Inc., ADT7475 Datasheet - Page 46

• Manufacturer Part Number: ADT7475
• Description: Dbcool Remote Thermal Monitor And Fan Controller
• Manufacturer: Analog Devices, Inc.

ADT7475
Enhanced Acoustics Register 1 (0x62)
Bit 7 (MIN3) = 0, PWM3 is off (0% PWM duty cycle) when
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
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
temperature is below T
Bit 5 (MIN1) = 1, PWM1 runs at PWM1 minimum duty cycle
below T
Configuration Register 6 (0x10)
Bit 0 (SLOW Remote 1), 1 slows the ramp rate for PWM
changes associated with the Remote 1 temperature channel by 4.
Bit 1 (SLOW Local), 1 slows the ramp rate for PWM changes
associated with the Local temperature channel by 4.
MIN
MIN
MIN
− T
− T
− T
HYST
HYST
HYST
.
.
.
AMBIENT TEMP
REMOTE 2 =
REMOTE 1 =
VRM TEMP
CPU TEMP
MIN
MIN
MIN
LOCAL =
100%
− T
− T
− T
0%
HYST
HYST
HYST
THERMAL CALIBRATION
THERMAL CALIBRATION
THERMAL CALIBRATION
.
.
.
T
T
T
T
Figure 61. The T
MIN
MIN
MIN
MIN
T
RANGE
T
T
T
RANGE
RANGE
RANGE
HYST
T
100%
100%
100%
THERM
0%
0%
0%
Value Applies to Fan On/Off Hysteresis and THERM Hysteresis
MUX
Rev. B | Page 46 of 68
PWM
PWM
PWM
MIN
MIN
MIN
CONFIG
CONFIG
CONFIG
Bit 2 (SLOW Remote 2), 1 slows the ramp rate for PWM
changes associated with the Remote 2 temperature channel by 4.
Bit 7 (ExtraSlow), 1 slows the ramp rate for all fans by a factor
of 39.2%.
The following sections list the ramp-up times when the SLOW
bit is set for each temperature monitoring channel.
Enhanced Acoustics Register 1 (0x62)
Bits [2:0] (ACOU1), select the ramp rate for PWM outputs
associated with the Remote 1 temperature input.
TACHOMETER 1
MEASUREMENT
TACHOMETER 2
MEASUREMENT
TACHOMETER 3
MEASUREMENT
PWM
PWM
PWM
GENERATOR
GENERATOR
GENERATOR
000 = 37.5 sec
001 = 18.8 sec
010 = 12.5 sec
011 = 7.5 sec
100 = 4.7 sec
101 = 3.1 sec
110 = 1.6 sec
111 = 0.8 sec
AND 4
PWM
PWM
PWM
ENHANCEMENT)
ENHANCEMENT)
ENHANCEMENT)
(ACOUSTIC
(ACOUSTIC
(ACOUSTIC
CONTROL
CONTROL
CONTROL
RAMP
RAMP
RAMP
PWM1
TACH1
PWM2
TACH2
PWM3
TACH3
FRONT CHASSIS
REAR CHASSIS
CPU FAN SINK