Pin Configuration And Function Descriptions - Analog Devices dBCool ADT7476 Manual

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

Table 4. Pin Function Descriptions
Pin No. Mnemonic Description
1 SDA Digital I/O (Open Drain). SMBus bidirectional serial data. Requires SMBus pull-up.
2 SCL Digital Input (Open Drain). SMBus serial clock input. Requires SMBus pull-up.
3 GND Ground Pin.
4 V Power Supply. Powered by 3.3 V standby, if monitoring in low power states is required. V
CC
through this pin.
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5 VID0 Digital Input. Voltage supply readouts from CPU. This value is read into the VID code register (0x43).
GPIO0 General-Purpose Open-Drain Digital I/O.
6 VID1 Digital Input. Voltage supply readouts from CPU. This value is read into the VID code register (0x43).
GPIO1 General-Purpose Open-Drain Digital I/O.
7 VID2 Digital Input. Voltage supply readouts from CPU. This value is read into the VID code register (0x43).
GPIO2 General-Purpose Open-Drain Digital I/O.
8 VID3 Digital Input. Voltage supply readouts from CPU. This value is read into the VID code register (0x43).
GPIO3 General-Purpose Open-Drain Digital I/O.
9 TACH3 Digital Input (Open Drain). Fan tachometer input to measure speed of Fan 3.
10 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.
11 TACH1 Digital Input (Open Drain). Fan tachometer input to measure speed of Fan 1.
12 TACH2 Digital Input (Open Drain). Fan tachometer input to measure speed of Fan 2.
13 PWM3 Digital I/O (Open Drain). Pulse-width modulated output to control Fan 3 and Fan 4 speed. Requires 10 kΩ typical
pull-up. Can be configured as a high or low frequency drive.
ADDREN If pulled low on power-up, the ADT7476 enters address select mode, and the state of Pin 14 (ADDR SELECT)
determines the ADT7476 slave address.
14 TACH4 Digital Input (Open Drain). Fan tachometer input to measure speed of Fan 4.
THERM Alternatively, the pin can be reconfigured as a bidirectional THERM pin. Use to time and monitor assertions on
the THERM input. For example, can be connected to the PROCHOT output of an Intel® Pentium® 4 processor or
to the output of a trip point temperature sensor. Can be used as an output to signal overtemperature
conditions.
SMBALERT Digital Output (Open Drain). This pin can be reconfigured as an SMBALERT interrupt output to signal out-of-
limit conditions.
GPIO6 General-Purpose Open-Drain Digital I/O.
ADDR SELECT If in address select mode, the logic state of this pin defines the SMBus device address.
15 D2– Cathode Connection to Second Thermal Diode.
16 D2+ Anode Connection to Second Thermal Diode.
SDA
1
SCL
2
GND
3
V
4
CC
VID0/GPIO0
5 ADT7476
TOP VIEW
VID1/GPIO1
6
(Not to Scale)
VID2/GPIO2
7
VID3/GPIO3
8
TACH3
9
PWM2/SMBALERT
10
TACH1 11
TACH2
12
Figure 3. Pin Configuration
Rev. B | Page 7 of 72
PWM1/XTO
24
V
23
CCP
+2.5V /THERM
22
IN
21 +12V /VID5
IN
+5V
20
IN
VID4/GPIO4
19
D1+
18
D1–
17
D2+
16
D2–
15
TACH4/THERM/SMBALERT/GPIO6/ADDR SELECT
14
PWM3/ADDREN
13
ADT7476
is also monitored
CC