ADT7463
PIN FUNCTION DESCRIPTIONS
Description
Pin No. Mnemonic
1
2
3
4
SDA
SCL
GND
VCC
Digital I/O (Open Drain). SMBus bidirectional serial data. Requires SMBus.
Digital Input (Open Drain). SMBus serial clock input. Requires SMBus pull-up.
Ground Pin for the ADT7463.
Power Supply. Can be powered by 3.3 V standby if monitoring in low power states is required. VCC is also
monitored through this pin. The ADT7463 can also be powered from a 5 V supply. Setting Bit 7 of Configura-
tion Register 1 (Reg. 0x40) rescales the VCC input attenuators to correctly measure a 5 V supply.
5
6
7
8
9
VID0
VID1
VID2
VID3
TACH3
Digital Input (Open Drain). Voltage supply readouts from CPU. This value is read into the VID register (Reg. 0x43).
Digital Input (Open Drain). Voltage supply readouts from CPU. This value is read into the VID register (Reg. 0x43).
Digital Input (Open Drain). Voltage supply readouts from CPU. This value is read into the VID register (Reg. 0x43).
Digital Input (Open Drain). Voltage supply readouts from CPU. This value is read into the VID register (Reg. 0x43).
Digital Input (Open Drain). Fan tachometer input to measure speed of Fan 3. Can be reconfigured as an analog
input (AIN3) to measure the speed of 2-wire fans.
10
PWM2
Digital Output (Open Drain). Requires 10 kΩ typical pull-up. Pulse-width modulated output to control FAN 2
speed.
SMBALERT
TACH1
TACH2
PWM3
Digital Output (Open Drain). This pin may be reconfigured as an SMBALERT interrupt output to signal
out-of-limit conditions.
11
12
13
Digital Input (Open Drain). Fan tachometer input to measure speed of Fan 1. Can be reconfigured as an analog
input (AIN1) to measure the speed of 2-wire fans.
Digital Input (Open Drain). Fan tachometer input to measure speed of Fan 2. Can be reconfigured as an analog
input (AIN2) to measure the speed of 2-wire fans.
Digital I/O (Open Drain). Pulse-width modulated output to control Fan 3/Fan 4 speed. Requires 10 kΩ typical
pull-up.
ADDRESS ENABLE If pulled low on power-up, this places the ADT7463 into address select mode, and the state of Pin 14 will determine
the ADT7463’s slave address.
14
TACH4
Digital Input (Open Drain). Fan tachometer input to measure speed of Fan 4. Can be reconfigured as an analog
input (AIN4) to measure the speed of 2-wire fans.
ADDRESS
SELECT
If in address select mode, this pin determines the SMBus device address.
THERM
Alternatively, the pin may be reconfigured as a bidirectional THERM pin. Can be used to time and monitor
assertions on the THERM input. For example, can be connected to the PROCHOT output of Intel’s Pentium 4
processor or to the output of a trip point temperature sensor. Can be used as an output to signal
overtemperature conditions.
15
16
17
18
19
20
D2–
Cathode Connection to Second Thermal Diode.
D2+
Anode Connection to Second Thermal Diode.
D1–
Cathode Connection to First Thermal Diode.
D1+
Anode Connection to First Thermal Diode.
VID4
+5VIN
THERM
Digital Input (Open Drain). Voltage supply readouts from CPU. This value is read into the VID register (Reg. 0x43).
Analog Input. Monitors 5 V power supply.
Alternatively, this pin may be reconfigured as a bidirectional THERM pin. Can be used to time and monitor
assertions on the THERM input. For example, can be connected to the PROCHOT output of Intel’s Pentium 4
processor or to the output of a trip point temperature sensor. Can be used as an output to signal
overtemperature conditions.
21
22
+12VIN
VID5
Analog Input. Monitors 12 V power supply.
Digital Input (Open Drain). Voltage supply readouts from CPU. This value is read into the VID register (Reg. 0x43).
Supports VRM10 solutions.
+2.5VIN
Analog Input. Monitors 2.5 V supply, typically a chipset voltage.
SMBALERT
Digital Output (Open Drain). This pin may be reconfigured as an SMBALERT interrupt output to signal
out-of-limit conditions.
23
24
VCCP
Analog Input. Monitors processor core voltage (0 V to 3 V).
PWM1/
XTO
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 XOR tree in XOR test mode.
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