f75375 Feature Integration Technology Inc., f75375 Datasheet - Page 15

• Manufacturer Part Number: f75375
• Description: Fintek Hardware Monitor Ic Datasheet
• Manufacturer: Feature Integration Technology Inc.

And the suggested application circuit for linear fac control would be:
The duty cycle of PWM can be programmed by a 8-bit register which are defined in the CR76h and CR86h. The default
duty cycle is set to 100%, that is, the default 8-bit registers is set to FFh. The expression of duty can be represented as
follows.
6.3.2
There are 3 modes to control fan speed and they are manual, fan speed mode and temperature mode. For manual
6.3.1.2 PWM duty Fan Control
Fintek
PWM Clock Input
Fan speed control mechanism
Output_vol
DC OUTPUT VOLTAGE
Duty_cycle
G
D
S
R1
NMOS
Figure 5-9
tage
3.9K
+12V
(V)
R
R2
(%)
=
3
2
=
3
12V
3 .
+
-
+
-
Programmed
×
PNP Transistor
C
Programmed
LM358
DC FAN Control with OP
1
R 10K
FAN
PMOS
9
- 8
C
47u
255
bit
- 8
PWM Clock Input
JP1
CON3
255
Feature Integration Technology Inc.
Register
bit
3
2
1
1N4148
Register
D1
Value
C
0.1u
F75375S/F75375SG
G
Value
D
S
R
4.7K
R1
NMOS
×
R 27K
Figure 5-10
100
R
10K
×
+5V
100
FANIN MONITOR
%
R2
%
+
-
PNP Transistor
C
FAN
July 2007
V0.26P