ADT7475 Analog Devices, Inc., ADT7475 Datasheet - Page 6

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

ADT7475
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
Table 4. Pin Function Descriptions
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Mnemonic
SCL
GND
V
TACH3
PWM2
SMBALERT
TACH1
TACH2
PWM3
TACH4
THERM
GPIO
SMBALERT
D2−
D2+
D1−
D1+
V
PWM1
XTO
SDA
CC
CCP
Description
Digital Input (Open Drain). SMBus serial clock input. Requires SMBus pull-up.
Ground Pin.
Power Supply. V
Digital Input (Open Drain). Fan tachometer input to measure speed of Fan 3.
PWM2: Digital Output (Open Drain). Requires 10 kΩ typical pull-up. Pulse-width modulated output to
control Fan 2 speed. Can be configured as a high or low frequency drive.
SMBALERT: Digital Output (Open Drain). This pin can be reconfigured as an SMBALERT interrupt output
to signal out-of-limit conditions.
Digital Input (Open Drain). Fan tachometer input to measure the speed of Fan 1.
Digital Input (Open Drain). Fan tachometer input to measure the speed of Fan 2.
Digital I/O (Open Drain). Pulse-width modulated output to control the speed of Fan 3 and Fan 4. Requires
10 kΩ typical pull-up. Can be configured as a high or low frequency drive.
TACH4: Digital Input (Open Drain). Fan tachometer input to measure the speed of Fan 4.
THERM: Digital I/O (Open Drain). Alternatively, this pin can be reconfigured as a bidirectional THERM pin
that can be used to time and monitor assertions on the THERM input. For example, the pin can be
connected to the PROCHOT output of an Intel® Pentium® 4 processor or to the output of a trip point
temperature sensor. This pin can be used as an output to signal overtemperature conditions.
GPIO: General-Purpose Open Drain Digital I/O.
SMBALERT: Digital Output (Open Drain). This pin can be reconfigured as an SMBALERT interrupt output
to signal out-of-limit conditions.
Cathode Connection to Second Thermal Diode.
Anode Connection to Second Thermal Diode.
Cathode Connection to First Thermal Diode.
Anode Connection to First Thermal Diode.
Analog Input. Monitors processor core voltage (0 V to 3 V).
Digital Output (Open Drain). Pulse-width modulated output to control Fan 1 speed. Requires 10 kΩ
typical pull-up.
Also functions as the output from the XNOR tree in XNOR test mode.
Digital I/O (Open Drain). SMBus bidirectional serial data. Requires 10 kΩ typical pull-up.
PWM2/SMBALERT
TACH3
TACH1
TACH2
PWM3
GND
SCL
V
CC
CC
is also monitored through this pin.
1
2
3
4
5
6
7
8
(Not to Scale)
Figure 3. Pin Configuration
ADT7475
TOP VIEW
Rev. B | Page 6 of 68
16
15
14
13
12
11
10
9
SDA
PWM1/XTO
V
D1+
D1–
D2+
D2–
TACH4/THERM/GPIO/SMBALERT
CCP