THMC50_08 Datasheet, PDF (14/34 Pages) Texas Instruments – REMOTE/LOCAL TEMPERATURE MONITOR AND FAN CONTROLLER WITH SMBus INTERFACE

THMC50
REMOTE/LOCAL TEMPERATURE MONITOR AND
FAN CONTROLLER WITH SMBus INTERFACE
SLIS090 – JULY 1999
PRINCIPLES OF OPERATION
analog output - FAN_SPD (continued)
+12 V
R1
100 kΩ
R2
100 kΩ
FAN_SPD/NTEST_IN
R5
5 kΩ
Q1/Q2
MBT3904
DUAL
Q3
IRF9620
R3
3.9 kΩ
R4
1 kΩ
Figure 9. External Fan Drive Circuit Using Discrete Components With P-Channel FET, Single Supply
+12 V
R2
100 k Ω
Q3
IRF9620
FAN_SPD/NTEST_IN
Q1/Q2
MBT3904
DUAL
R3
39 kΩ
R4
10 kΩ
–12 V
R1
4.7 kΩ
Figure 10. External Fan Drive Circuit Using Discrete Components With P-Channel FET, Dual Supply
+12 V
R1
100 kΩ
R2
100 kΩ
FAN_SPD/NTEST_IN
R6
5 kΩ
Q1/Q2
MBT3904
DUAL
Q3
BC556
2N3906
R5
100 Ω
Q4
BD132
TIP32A
R3
3.9 kΩ
R4
1 kΩ
Figure 11. External Fan Drive Circuit Using Discrete Components and
PNP Output Transistor, Single Supply
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