W83637HF Datasheet, PDF (32/149 Pages) Winbond – LPC I/O

W83637HF
6.3.1 Monitor over 4.096V voltage
The +12V input voltage can be expressed as following equation.
VIN1
=
V₁
×
R₁
R
2
+ 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 VIN1 can be subject to less than 4.096V for the maximun input
range of the 8-bit ADC.
The -12V input voltage can be expressed as following equation.
VIN 2
=
(V₂
−
3.6) ×
R₄
R3 + R4
+
3.6, whereV₂
=
−12
The value of R3 and R4 can be selected to 56K Ohms and 232K Ohms, respectively, when the input
voltage V2 is -12V. The node voltage of VIN2 can be subject to less than 4.096V for the maximun input
range of the 8-bit ADC.
The Pin 114 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 W83637HF and the second function is
that this voltage with 5V is connected to internal serial resistors to monitor the +5V voltage. The
W83637HF internal two serial resistors are 34K ohms and 51K ohms so that input voltage to ADC is
3V which is less than 4.096V of ADC maximum input voltage. The express equation can represent as
follows.
V_in
= VCC ×
51KΩ
51KΩ + 34KΩ
≅
3V
where VCC is set to 5V.
The Pin 61 is connected to 5VSB voltage. W83637HF monitors this voltage and the internal two serial
resistors are 34K Ω and 51K Ω so that input voltage to ADC is 3V which less than 4.096V of ADC
maximum input voltage.
6.3.2 CPUVCORE voltage detection method
W83637HF provides two detection methods for CPUVCORE(pin100).
(1). VRM8 method:
The LSB of this mode is 16mV. This means that the detected voltage equals to the reading of
this voltage register multiplies 16mV. The formula is as the following:
Detected Voltage = Re ading ∗ 0.016 V
(2). VRM9 method:
The LSB of this mode is 4.88mV which is especially designed the low voltage CPU. The
formula is as the following:
Detected Voltage = Re ading ∗ 0.00488 + 0.7 V
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Publication Release Date: June 25, 2003
Revision 1.3