ADT7476 Analog Devices, Inc., ADT7476 Datasheet - Page 42

• Manufacturer Part Number: ADT7476
• Description: Dbcool Remote Thermal Controller And Voltage Monitor
• Manufacturer: Analog Devices, Inc.

ADT7476
Mux Configuration Example
This is an example of how to configure the mux in a system
using the ADT7476 to control three fans. The CPU fan sink is
controlled by PWM1, the front chassis fan is controlled by
PWM2, and the rear chassis fan is controlled by PWM3. The
mux is configured for the following fan control behavior:
•
•
•
PWM1 (CPU fan sink) is controlled by the fastest speed
calculated by the local (VRM temperature) and Remote 2
(processor) temperature. In this case, the CPU fan sink is
also used to cool the VRM.
PWM2 (front chassis fan) is controlled by the Remote 1
temperature (ambient).
PWM3 (rear chassis fan) is controlled by the Remote 1
temperature (ambient).
AMBIENT TEMP
REMOTE 1 =
REMOTE 2 =
VRM TEMP
CPU TEMP
LOCAL =
THERMAL CALIBRATION
THERMAL CALIBRATION
THERMAL CALIBRATION
T
T
T
MIN
MIN
MIN
Figure 51. Assigning Temperature Channels to Fan Channels
T
T
T
RANGE
RANGE
RANGE
100%
100%
100%
0%
0%
0%
MUX
Rev. B | Page 42 of 72
MUX
PWM
PWM
PWM
MIN
MIN
MIN
CONFIG
CONFIG
CONFIG
Example Mux Settings
Bits [7:5] (BHVR), PWM1 Configuration Register 0x5C.
Bits [7:5] (BHVR), PWM2 Configuration Register 0x5D.
Bits [7:5] (BHVR), PWM3 Configuration Register 0x5E.
These settings configure the mux, as shown in Figure 52.
TACHOMETER 1
MEASUREMENT
TACHOMETER 2
MEASUREMENT
TACHOMETER 3
MEASUREMENT
PWM
PWM
PWM
GENERATOR
GENERATOR
GENERATOR
101 = Fastest speed calculated by local and Remote 2
temperature controls PWM1
000 = Remote 1 temperature controls PWM2
000 = Remote 1 temperature controls PWM3
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