W83783S Datasheet, PDF (18/57 Pages) Winbond – MONITORING IC

W83783S
Preliminary
6.3.3 Monitor temperature from thermistor:
The W83783S 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 11, the themistor is connected by a serial resistor with 10K Ohms, then
connect to VREF (Pin 37).
6.3.4 Monitor temperature from Pentium II^TM thermal diode or bipolar transistor 2N3904
The W83783S can alternate the thermistor to Pentium II^TM (Deschutes) thermal diode interface or
transistor 2N3904 and the circuit connection is shown as Figure 12. The pin of Pentium II^TM D- is
connected to power supply ground (GND) and the pin D+ is connected to pin PIIx in the W83783S.
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.
Bipolar Transistor
Temperature Sensor
C
B _2N3904
E
OR
Pentium II
CPU
D+
Therminal
Diode
D-
R=30K, 1%
VREF
PIITDx
C=3300pF
R=30K, 1%
W83783S
PIITDx
C=3300pF
Figure 12.
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Publication Release Date: April 1999
Revision 0.55