ADM1030
RELEVANT REGISTERS FOR AUTOMATIC FAN SPEED
CONTROL MODE
Register 0x00 Configuration Register 1
Register 0x24 Local Temp T
MIN
/T
RANGE
<7>
Logic 1 selects Automatic Fan Speed Control, Logic 0
selects software control (Default = 1).
<6:5> 00 = Remote Temperature controls Fan
11 = Fastest Calculated Speed controls the fan when
Bit 7 = Logic 1.
Register 0x20 Fan Characteristics Register 1
<2:0> Fan 1 Spin-Up Time
000 = 200 ms
001 = 400 ms
010 = 600 ms
011 = 800 ms
100 = 1 sec
101 = 2 secs (Default)
110 = 4 secs
111 = 8 secs
<5:3> PWM Frequency Driving the Fan
000 = 11.7 Hz
001 = 15.6 Hz
010 = 23.4 Hz
011 = 31.25 Hz (Default)
100 = 37.5 Hz
101 = 46.9 Hz
110 = 62.5 Hz
111 = 93.5 Hz
<7:6> Speed Range N; defines the lowest fan speed that can be
measured by the device.
00 = 1: Lowest Speed = 2647 RPM
01 = 2: Lowest Speed = 1324 RPM
10 = 4: Lowest Speed = 662 RPM
11 = 8: Lowest Speed = 331 RPM
Register 0x22 Fan Speed Configuration Register
<7:3> Local Temp T
MIN
. These bits set the temperature at
which the fan will turn on when under Auto Fan Speed
Control. T
MIN
can be programmed in 4°C increments.
00000 = 0°C
00001 = 4°C
00010 = 8°C
00011 = 12°C
|
|
01000 = 32°C (Default)
|
|
11110 = 120°C
11111 = 124°C
<2:0> Local Temperature T
RANGE
. This nibble sets the tem-
perature range over which Automatic Fan Speed Control
takes place.
000 = 5°C
001 = 10°C
010 = 20°C
011 = 40°C
100 = 80°C
Register 0x25 Remote Temperature T
MIN
/T
RANGE
<3:0> Min Speed: This nibble contains the speed at which the
fan will run when the temperature is at T
MIN
. The default
is 0x05, meaning that the fan will run at 33% duty cycle
when the temperature is at T
MIN
.
<7:3> Remote Temperature T
MIN
. Sets the temperature at
which the fan will switch on based on Remote Tempera-
ture Readings.
00000 = 0°C
00001 = 4°C
00010 = 8°C
00011 = 12°C
|
|
01100 = 48°C
|
|
11110 = 120
°
C
11111 = 124
°
C
<2:0> Remote Temperature T
RANGE
. This nibble sets the tem-
perature range over which the fan will be controlled based
on Remote Temperature readings.
000 = 5°C
001 = 10°C
010 = 20°C
011 = 40°C
100 = 80°C
REV. 0
–15–
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