W83627DHG
Publication Release Date: Aug, 22, 2007
-31- Version
1.4
7.3 Analog
Inputs
The maximum input voltage on analog pins is 2.048 V because the 8-bit ADC has an 8-mV LSB.
Usually, the voltage ports of CPU Vcore (pin 100), battery (pin 74), 3VSB (pin 61), 3VCC (pin 12), and
AVCC (pin 95) can be directly connected to their respective analog pins, as illustrated in the figure
below.
As illustrated in the figure above, other connections may require some external circuits. The rest of this
section provides more information about voltages outside the range of the 8-bit ADC, CPU Vcore
voltage detection, and temperature sensing
7.3.1 Voltages Over 2.048 V or Less Than 0 V
Input voltages greater than 2.048 V should be reduced by external resistors to keep the input voltages
in the proper range. For example, input voltage V
0
(+12 V) should be reduced before it is connected to
VIN0 according to the following equation:
2
1
2
0
0
R
R
R
V
VIN
+
×
=
Pin 97
VIN2
CPUVCORE
Pin 100
Pin 99
VIN0
VIN1
VBAT
Pin 98
Pin 74
R4
R1
V0
Positive Voltage Input
Negative Voltage Input
8-bit ADC
with
8mV LSB
10K, 1%
R
THM
VREF
Pin 101
AUXTIN
CPUTIN
SYSTIN
Pin 102
Pin 103
Pin 104
3VSB
Pin 61
R3
10K@25 C, beta=3435K
R2
R
V1
AVCC
Pin 95
Power Inputs
15K, 1%
R
CAP,2200p
CPUD+
CPUD-
(AGND)
Pin 12
3VCC
Pin 96
VIN3
CPUD-(AGND) Pin 105
Summary of Contents for W83627DHG
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