NCT6627UD Nuvoton Technology Corporation of America, NCT6627UD Datasheet - Page 42

• Manufacturer Part Number: NCT6627UD
• Manufacturer: Nuvoton Technology Corporation of America

Specifications of NCT6627UD

• Lead Free Status / Rohs Status: Supplier Unconfirmed

Input voltages greater than 2.048 V should be reduced by an external resistor divider to keep the input voltages in
the proper range. For example, input voltage V
according to the following equation:
R1 and R2 can be set to 150 KΩ and 10 KΩ, respectively, to reduce V
The W83627UHG uses the same approach. Pins 12 and 48 provide two functions. One, these pins are connected
to 5VCC at +5 V to supply internal (digital / analog) power to the W83627UHG. Two, these pins monitor 5VCC.
The voltage value detected on Pin 12 and 48 can be calculated via the equation below:
Pin 61 is implemented likewise to monitor its +5 V stand-by power supply.
Pin 74 also has two internal, 20-KΩ serial resistors that reduce the ADC-input voltage to 1.65 V.
The voltage on Pin 97 AVCC can also be obtained via the equation below:
The CPUVCORE pin feeds directly into the ADC with no voltage divider since the nominal voltage on this pin is
only 1.2V.
Negative voltages are handled similarly, though the equation looks a little more complicated. For example,
negative voltage V2 (-5V) can be reduced according to the following equation:
R3 and R4 can be set to 120 KΩ and 10 KΩ, respectively, to reduce negative input voltage V
than 2.048 V. Note that R4 is referenced to VREF, or 2.048V instead of 0V to allow for more dynamic range. This
is simply good analog practice to yield the most precise measurements.
7.3.1 Voltages Over 2.048 V or Less Than 0 V
2. 4.28, 4.16, and 4.25 in the above equatiosn are the constants converted based on the resistors.
VIN
2
=
(
VBAT
5VSB
V
2
AVCC
−
5VCC
. 2
= Bank 5, CR[50h] x 1 LSB x 4.16*
= Bank 5, CR[51h] x 1 LSB x 4.25*
048
VIN
= CR[23h] x 1 LSB x 4.28*
= CR[22h] x 1 LSB x 4.16*
)
×
0
0
R
(+12 V) should be reduced before it is connected to VIN0
=
3
V
R
+
0
4
R
×
4
R
1
+
-33-
R
+
. 2
2
R
W83627UHG/NCT6627UD
048
2
,
0
whereV
from +12 V to less than 2.048 V.
Publication Release Date: October 26, 2010
2
=
−
5
2
from – 5 V to less
Revision 1.7