ADT7468 Analog Devices, Inc., ADT7468 Datasheet - Page 43

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

STEP 2: CONFIGURING THE MUX
After the system hardware configuration is determined, the fans
can be assigned to particular temperature channels. Not only
can fans be assigned to individual channels, but the behavior of
the fans is also configurable. For example, fans can run under
automatic fan control, they can run manually (under software
control), or they can run at the fastest speed calculated by
multiple temperature channels. The mux is the bridge between
temperature measurement channels and the three PWM
outputs.
Bits <7:5> (BHVR) of Registers 0x5C, 0x5D, and 0x5E (PWM
configuration registers) control the behavior of the fans
connected to the PWM1, PWM2, and PWM3 outputs. The
values selected for these bits determine how the mux connects a
temperature measurement channel to a PWM output.
Automatic Fan Control MUX Options
<7:5> (BHVR), Registers 0x5C, 0x5D, 0x5E.
000 = Remote 1 temperature controls PWMx
001 = local temperature controls PWMx
010 = Remote 2 temperature controls PWMx
AMBIENT TEMP
REMOTE 1 =
REMOTE 2 =
VRM TEMP
CPU TEMP
LOCAL =
THERMAL CALIBRATION
THERMAL CALIBRATION
THERMAL CALIBRATION
T
T
T
MIN
MIN
MIN
T
T
T
Figure 56. Assigning Temperature Channels to Fan Channels
RANGE
RANGE
RANGE
100%
100%
100%
0%
0%
0%
MUX
Rev. A | Page 43 of 84
MUX
PWM
PWM
PWM
MIN
MIN
MIN
The fastest speed calculated options pertain to controlling one
PWM output based on multiple temperature channels. The
thermal characteristics of the three temperature zones can be
set to drive a single fan. An example would be the fan turning
on when Remote 1 temperature exceeds 60°C or if the local
temperature exceeds 45°C.
Other MUX Options
<7:5> (BHVR), Registers 0x5C, 0x5D, 0x5E.
ENHANCEMENT)
ENHANCEMENT)
ENHANCEMENT)
TACHOMETER 1
MEASUREMENT
TACHOMETER 2
MEASUREMENT
MEASUREMENT
TACHOMETER 3
101 = Fastest speed calculated by local and Remote 2
temperature controls PWMx
110 = Fastest speed calculated by all three temperature
channels controls PWMx
011 = PWMx runs full speed
100 = PWMx disabled (default)
111 = manual mode. PWMx is runner under software
control. In this mode, PWM duty cycle registers
(Registers 0x30 to 0x32) are writable and control the
PWM outputs.
(ACOUSTIC
(ACOUSTIC
(ACOUSTIC
CONTROL
CONTROL
CONTROL
RAMP
RAMP
RAMP
AND 4
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
ADT7468