W83792AD/AG/D/G
7.6 Analog Inputs
The maximum input voltage of the analog pin is 4.096V because the 10-bit ADC has a 4mv LSB.
Actually, the application of the PC monitoring would most often be connected to power supply. The
CPU V-core voltage, +3.3V and battery voltage can directly connect to these analog inputs. The –
5V, –12V and +12V inputs should be reduced a factor with external resistors to meet the input range.
As Figure 4 shows.
*PS : VCORE channel resolution = 2mv VIN0-4 channel resolution = 4mv
Pin 36
VcoreA
Pin 35
VcoreB
Positive Inputs
Pin 34
Pin 30
+3.3VIN
VBAT
R1
12VIN
Pin 32
V1
10-bit ADC
with
4mV LSB
R2
Positive Input
Negative Input
R5
N12VIN
N5VIN
Pin 31
Pin 33
V3
V4
R7
R6
R8
R
10K, 1%
VREF
VTIN3
Pin 37
Pin 38
Typical Thermister Connection
Pin 39
Pin 40
VTIN2
VTIN1
R
THM
10K, 25 C
**The Connections of VTIN1 and VTIN2
are same as VTIN3
Figure 4.
7.6.1 Monitor over 4.096V voltage:
The input voltage +12VIN can be expressed as the following equation.
R2
12VIN = V1 ×
R1 + R2
The value of R1 and R2 can be selected to 28K Ohms and 10K Ohms, respectively, when the input
voltage V1 is 12V. The node voltage of +12VIN should be subject to under 4.096V for the maximum
input range of the 8-bit ADC. The pin 13 and pin 29 are discretely connected to the power supply +5V
and 5VSB . There are two functions in these pins with 5V. The first function is to supply internal analog
power in the W83792D and the second one is that these voltages are all connected to internal serial
resistors to monitor the +5V and 5VSB voltage.
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