W83637HF_06 Datasheet, PDF (33/151 Pages) Winbond – LPC I/O

W83637HF/HG
6.3.3 Temperature Measurement Machine
The temperature data format is 8-bit two's-complement for sensor SYSTIN and 9-bit two's-complement
for sensor CPUTIN and VTIN. The 8-bit temperature data can be obtained by reading the CR[27h]. The
9-bit temperature data can be obtained by reading the 8 MSBs from the Bank1/Bank2 CR[50h] and the
LSB from the Bank1/Bank2 CR[51h] bit 7. The format of the temperature data is show in Table 1.
Temperature
+125°C
+25°C
+1°C
+0.5°C
+0°C
-0.5°C
-1°C
-25°C
-55°C
8-Bit Digital Output
8-Bit Binary
8-Bit Hex
0111,1101
7Dh
0001,1001
19h
0000,0001
01h
-
-
0000,0000
00h
-
-
1111,1111
FFh
1110,0111
E7h
1100,1001
C9h
Table 1
9-Bit Digital Output
9-Bit Binary
9-Bit Hex
0,1111,1010
0FAh
0,0011,0010
032h
0,0000,0010
002h
0,0000,0001
001h
0,0000,0000
000h
1,1111,1111
1FFh
1,1111,1110
1FFh
1,1100,1110
1CEh
1,1001,0010
192h
6.3.3.1 Monitor temperature from thermistor:
The W83637HF can connect three thermistors to measure three different envirment temperature. The
specification of thermistor should be considered to (1) β value is 3435K, (2) resistor value is 10K ohms
at 25°C. In the Figure 6.2, the themistor is connected by a serial resistor with 10K Ohms, then connect
to VREF (Pin 101).
6.3.3.2 Monitor temperature from Pentium II^TM/Pentium III^TM thermal diode or bipolar
transistor2N3904
The W83637HF can alternate the thermistor to Pentium II^TM/Pentium III^TM thermal diode interface or
transistor 2N3904 and the circuit connection is shown as Figure 6.3. The pin of Pentium II^TM/Pentium
III^TM D- is connected to pin 111(CPUD-) and the pin D+ is connected to temperature sensor pin in the
W83637HF. The resistor R=30K ohms should be connected to VREF to supply the diode bias current
and the bypass capacitor C=3300pF should be added to filter the high frequency noise. The transistor
2N3904 should be connected to a form with a diode, that is, the Base (B) and Collector (C) in the
2N3904 should be tied together to act as a thermal diode.
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Publication Release Date: March, 2006
Revision 1.6