W83L786NR Datasheet, PDF (16/50 Pages) Winbond – H/W Monitoring IC

W83L786NR/ W83L786NG
7.5 Temperature Measurement Machine
The temperature data format is 8-bit unsigned for thermal sensor. The 8-bit temperature data can be
obtained by reading the VR [25h] or VR [26h]. The format of the temperature data is shown in Table 1.
TEMPERATURE
+160°C
+25°C
+2°C
+1°C
+0°C
8-BIT BINARY
1010,0000
0001,1001
0000,0010
0000,0001
0000,0000
8-BIT DIGITAL OUTPUT
8-BIT HEX
A0h
19h
02h
01h
00h
Table 1
7.5.1 Monitor Temperature from Thermistor
The W83L786NR/NG can connect one thermistor and one thermal diode sensor to measure two
different environment temperatures. The specification of thermistor should be considered to (1) β
value is 3435 K, and (2) resistor value is 10K ohms at 25°C. In the Figure 3, the themistor is
connected by a serial resistor with 10K Ohms, and then connect to V_REF (pin 15).
7.5.2 Monitor Temperature from Thermal Diode
The W83L786NR/NG can alternate the thermistor to thermal diode interface and the circuit connection
is shown as Figure 5. The pin of D- is connected to power supply ground (GND) and the pin D+ is
connected to pin D+ or VTIN1 in the W83L786NR/NG. The bypass capacitor C=2200pF should be
added to filter the high frequency noise.
D+
CPU or GPU
T herm inal
D iode
D-
C=2200pF
D+
D-
W 83L786NR
B ipolar T ransistor
T em perature sensor
2N3904
C=2200pF
V T IN 1
Figure 5
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Publication Release Date: March 31, 2006
Revision 0.9