w83627hg Winbond Electronics Corp America, w83627hg Datasheet - Page 37

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

The Pin 61 is connected to 5VSB voltage. W83627HF monitors this voltage and the internal two serial
resistors are 17K : and 33K : so that input voltage to ADC is 3.3V which less than 4.096V of ADC
maximum input voltage.
7.3.2
The negative voltage should be connected two series resistors and a positive voltage VREF °is
equal to 3.6V±. In the Figure 8.2, the voltage V2 and V3 are two negative voltage which they are -
12V and -5V respectively. The voltage V2 is connected to two serial resistors then is connected to an-
other terminal VREF which is positive voltage. So as that the voltage node N12VIN can be obtain a
posedge voltage if the scales of the two serial resirtors are carefully selected. It is recommanded from
Winbond that the scale of two serial resistors are R3=232K ohm and R4=56K ohm. The input voltage
of node N12VIN can be calculated by following equation.
If the V2 is equal to -12V then the voltage is equal to 0.567V and the converted hexdecimal data is set
to 35h by the 8-bit ADC with 16mV-LSB.This monitored value should be converted to the real negative
votage and the express equation is shown as follows.
Where E is 232K/°232K+56K±. If the N2VIN is 0.567 then the V2 is approximately equal to -12V.
The another negative voltage input V3 °approximate -5V± also can be evaluated by the similar
method and the serial resistors can be selected with R5=120K ohms and R6=56K ohms by the Win-
bond recommended. The expression equation of V3 With -5V voltage is shown as follows.
Where the J is set to 120K/°120K+56K±. If the monitored ADC value in the N5VIN channel is
0.8635, VREF is 3.6V and the parameter J is 0.6818 then the negative voltage of V3 can be evalated
to be -5V.
Monitor negative voltageš
N VIN
12
V
in
(
V
VCC
VREF
V
Where VREF is equal 3.6V.
2
3
where VCC is set to 5V.
N VIN VREF
u
N VIN VREF

12
50
5
V
K
2
- 33 -
:
) (
50
1
1
u





K
:
232
J
34
E
K
K
232
:
:
u
u
#
J

K
E
W83627HF/ F/ HG/ G
2 98
Publication Release Date: June 09, 2006
:
56
.
K
V
:
)

V
2
Revision 2.27