w83627hg Winbond Electronics Corp America, w83627hg Datasheet - Page 36

• Manufacturer Part Number: w83627hg
• Description: Winbond Lpc I/o
• Manufacturer: Winbond Electronics Corp America

W83627HF/ F/ HG/ G
7.3
Analog Inputs
The maximum input voltage of the analog pin is 4.096V because the 8-bit ADC has a 16mv LSB.
Really, the application of the PC monitoring would most often be connected to power suppliers. The
CPU V-core voltage, +3.3V, battery and 5VSB voltage can directly connected to these analog inputs.
The +12V,-12V and -5V voltage inputs should be reduced a factor with external resistors so as to ob-
tain the input range. As Figure 8.2 shows.
Figure. 8.2
7.3.1
Monitor over 4.096V voltageš
The input voltage +12VIN can be expressed as following equation.
R
2
12
VIN
V
u
1
R

R
1
2
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 can be subject to less than 4.096V for the maximun
input range of the 8-bit ADC. The Pin 97 is connected to the power supply VCC with +5V. There are
two functions in this pin with 5V. The first function is to supply internal analog power in the W83627HF
and the second function is that this voltage with 5V is connected to internal serial resistors to monitor
the +5V voltage. The values of two serial resistors are 34K ohms and 50K ohms so that input voltage
to ADC is 2.98V which is less than 4.096V of ADC maximum input voltage. The express equation can
represent as follows.
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