ADT7468
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
SDA
SCL
GND
24 PWM1/XTO
1
V
2
23
22
21
CCP
+2.5V
3
IN
4
V
+12V /VID5
IN
CC
VID0
VID1
VID2
5
20 +5V /THERM
IN
6
19 VID4
18 D1+
ADT7468
TOP VIEW
7
(NOT TO SCALE)
8
17
VID3
TACH3
D1–
9
16
15
D2+
D2–
10
11
12
PWM2/SMBALERT
14 TACH4/GPIO/THERM/SMBALERT
TACH1
TACH2
13
PWM3
Figure 3. Pin Configuration
Table 3. Pin Function Descriptions
Pin
No.
1
Mnemonic Description
SDA
SCL
GND
VCC
Digital I/O (Open Drain). SMBus bidirectional serial data. Requires pull-up resistor.
Digital Input (Open Drain). SMBus serial clock input. Requires pull-up resistor.
Ground Pin.
2
3
4
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 ADT7468 can also be powered from a 5 V supply. Setting Bit 7 of Configuration 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.
Can be configured as a high or low frequency drive.
Digital Output (Open Drain). This pin can be reconfigured as an
conditions.
interrupt output to signal out-of-limit
SMBALERT
TACH1
TACH2
PWM3
SMBALERT
11
12
13
14
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 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 speed of Fan 4. Can be reconfigured as an analog input
(AIN4) to measure the speed of 2-wire fans.
GPIO
General Purpose Open Drain Digital I/O.
Alternatively, the pin can be reconfigured as a bidirectional
pin. Can be used to time and monitor assertions
THERM
THERM
on the
input. For example, this pin can be connected to the
output of an Intel Pentium 4 processor
PROCHOT
THERM
or to the output of a trip point temperature sensor. This pin can also be used as an output to signal overtemperature
conditions.
Digital Output (Open Drain). This pin can be reconfigured as an
conditions.
interrupt output to signal out-of-limit
SMBALERT
D2–
SMBALERT
15
Cathode Connection to Second Thermal Diode.
Rev. 3 | Page 6 of 81 | www.onsemi.com