f75334 Feature Integration Technology Inc., f75334 Datasheet - Page 15

• Manufacturer Part Number: f75334
• Description: Performance Controller
• Manufacturer: Feature Integration Technology Inc.

7. Function Description
7.1 Hardware monitor
the function/address before you implement this chip. Trapping table is as below.
2.048V. Therefore the voltage under 2.048V (ex:1.5V) can be directly connected to these
analog inputs. The voltage higher than 2.048V should be reduced by a factor with external
resistors so as to obtain the input range. Only 3Vcc is an exception for it is main power of the
F75334DG. Therefore 3Vcc can directly connect to this chip’s power pin and need no external
resistors. There are two functions in this pin with 3.3V. The first function is to supply internal
analog power of the F75334DG and the second function is that voltage with 3.3V is connected
to internal serial resistors to monitor the +3.3V voltage. The internal serial resistors are two
150K ohm, so that the internal reduced voltage is half of +3.3V.
is within the tolerance. As for application circuit, it can be refer to the figure shown as follows.
follows:
I2C address
Fan type
Pwm polarity
There are four voltage inputs in the F75334DG and the voltage divided formula is shown as
The F75334DG provides a pin27 for functions/addresses trapping. Remember to select
VIN
For the 8-bit ADC has the 8mv LSB, the maximum input voltage of the analog pin is
If we choose R1=27K, R2=5.1K, the exact input voltage for V+12v will be 1.907V, which
=
V
+
12
V
×
Pull down 4.7k
(00)
8’h66
DC (linear fan)
PWM_IN#
R
1
R
+
2
R
2
where V
Pull down 200k
(10)
8’h6A
DC (linear fan)
PWM_IN#
+12V
8
is the analog input voltage, for example.
Pull up 200k
(11)
8’h6C
PWM fan control
PWM_IN
Pull up 4.7k
(01)
8’h68
PWM fan control
PWM_IN
F75334
July, 2007
V0.25P