W83627DHG
Publication Release Date: Aug, 22, 2007
-32- Version
1.4
R1 and R2 can be set to 56 K
Ω
and 10 K
Ω
, respectively, to reduce V
0
from +12 V to less than 2.048 V.
The W83627DHG uses the same approach. Pins 12 and 95 provide two functions. One, these pins are
connected to VCC at +3.3 V to supply internal (digital / analog) power to the W83627DHG. Two, these
pins monitor VCC. The W83627DHG has two internal, 34-K
Ω
serial resistors that reduce the ADC-input
voltage to 1.65 V.
V
K
K
K
VCC
V
in
65
.
1
34
34
34
≅
Ω
+
Ω
Ω
×
=
, where VCC is set to 3.3V
Pin 61 is implemented likewise to monitor its +3.3 V stand-by power supply.
Negative voltages are handled similarly, though the equation looks a little more complicated. For
example, negative voltage V1 (-12V) can be reduced according to the following equation:
12
,
048
.
2
)
048
.
2
(
1
1
4
3
4
1
−
=
+
+
×
−
=
whereV
R
R
R
V
VIN
R3 and R4 can be set to 232 K
Ω
and 10 K
Ω
, respectively, to reduce negative input voltage V
1
from –12
V to less than 2.048 V.
Both of these solutions are illustrated in the figure above.
7.3.2 Voltage
Detection
The data format for voltage detection is an eight-bit value, and each unit represents an interval of 8 mV.
Detected Voltage = Reading * 0.008 V
If the source voltage was reduced, the detected voltage value may have to be scaled up accordingly.
7.3.3 Temperature
Sensing
The data format for sensor SYSTIN is 8-bit, two's-complement, and the data format for sensors
CPUTIN and AUXTIN is 9-bit, two's-complement. This is illustrated in the table below.
8-BIT DIGITAL OUTPUT
9-BIT DIGITAL OUTPUT
TEMPERATURE
8-BIT BINARY
8-BIT HEX
9-BIT BINARY
9-BIT HEX
+125
°
C
0111,1101 7Dh
0,1111,1010 0FAh
+25
°
C
0001,1001 19h
0,0011,0010 032h
+1
°
C
0000,0001 01h
0,0000,0010 002h
+0.5
°
C
- -
0,0000,0001
001h
+0
°
C
0000,0000 00h
0,0000,0000 000h
-0.5
°
C
- -
1,1111,1111
1FFh
-1
°
C
1111,1111 FFh
1,1111,1110 1FFh
-25
°
C
1110,0111 E7h
1,1100,1110 1CEh
-55
°
C
1100,1001 C9h
1,1001,0010 192h
Summary of Contents for W83627DHG
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