W83697HF Datasheet, PDF (96/167 Pages) Winbond – WINBOND I/O

W83697HF/F
9.3.3 Temperature Measurement Machine
The temperature data format is 8-bit two's-complement for sensor 1 and 9-bit two's-complement for
sensor 2. 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 CR[50h] and the LSB from the Bank1 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 2.
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
9.3.3.1 Monitor temperature from thermistor:
The W83697HF 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 9.2, the themistor is connected by a serial resistor with 10K Ohms, then connect to
VREF (Pin 101).
9.3.3.2 Monitor temperature from Pentium II^TM thermal diode or bipolar transistor 2N3904
The W83697HF can alternate the thermistor to Pentium II^TM (Deschutes) thermal diode interface or
transistor 2N3904 and the circuit connection is shown as Figure 9.3. The pin of Pentium II^TM D- is
connected to power supply ground (GND) and the pin D+ is connected to pin VTINx in the W83697HF.
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 togeter to act as a thermal diode.
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Publication Release Date: Feb. 2002
Revision 0.70