ADT7467 Analog Devices, Inc., ADT7467 Datasheet - Page 10

• Manufacturer Part Number: ADT7467
• Description: Dbcool Remote Thermal Monitor And Fan Controller
• Manufacturer: Analog Devices, Inc.

ADT7467
Configuration Register 5
Bit 0: If Bit 0 is set to 1, the ADT7467, in terms of temperature,
is backward compatible with the ADT7460. Measurements,
including T
range −127°C to +127°C. Also, care should be taken in
reprogramming the temperature limits (T
THERM ) to their desired twos complement value, because the
power-on default for them is at Offset 64. The extended
temperature range is −64°C to 191°C. The default is 1, which is
in the −64°C to +191°C temperature range.
Bit 1 = 0 is the high frequency (22.5 kHz) fan drive signal.
Bit 1 = 1 switches the fan drive to low frequency PWM,
programmable between 10 Hz and 100 Hz, the same as the
ADT7460. The default is 0, or HF PWM.
Bit 2 sets the direction for the GPIO: 0 = input, 1 = output.
Bit 3 sets the GPIO polarity: 0 = active low, 1 = active high.
Setting the Functionality of Pin 9
Pin 9 on the ADT7467 has four possible functions: SMBALERT ,
THERM , GPIO, and TACH4. The user chooses the required
functionality by setting Bit 0 and Bit 1 of Configuration Register
4 at Address 0x7D.
MIN
calibration circuit and fan control, work in the
FRONT
CHASSIS
FAN
REAR
CHASSIS
FAN
AMBIENT
TEMPERATURE
MIN
, operating point,
Figure 15. ADT7467 Configuration
TACH2
PWM3
TACH3
D1+
D1–
Rev. A | Page 10 of 80
ADT7467
GND
SMBALERT
THERM
TACH1
PWM1
Table 4. Pin 9 Settings
Bit 1
0
0
1
1
RECOMMENDED IMPLEMENTATION
Configuring the ADT7467 as in Figure 15 allows the system
designer to use the following features:
•
•
•
•
•
•
SDA
SCL
D2+
D2–
Two PWM outputs for fan control of up to three fans (the
front and rear chassis fans are connected in parallel).
Three TACH fan speed measurement inputs.
V
CPU temperature measured using the Remote 1
temperature channel.
Ambient temperature measured through the Remote 2
temperature channel.
Bidirectional THERM pin. This feature allows Intel
Pentium 4 PROCHOT monitoring and can function as an
overtemperature THERM output. Alternatively, it can be
programmed as an SMBALERT system interrupt output.
CC
PROCHOT
measured internally through Pin 3.
Bit 0
0
1
0
1
CPU FAN
Function
TACH4
THERM
SMBALERT
GPIO
CPU
ICH