Fintek
Feature Integration Technology Inc.
F75373
connected by a serial resistor with 10K Ohm, then connect to VREF (pin13).
5.3.2 Over Temperature Signal (OVT#)
The F75373S can provide two external thermal sensors to detect temperature. When monitored temperature exceeds the
over-temperature threshold value, OVT# will be asserted until the temperature goes below the hysteresis temperature.
To
T
HYST
OVT#
Figure 5-4
5.4 Fan
5.4.1 Fan speed count
Inputs are provided by the signals from fans equipped with tachometer outputs. The level of these signals should be set to TTL
level, and maximum input voltage cannot be over VCC. If the input signals from the tachometer outputs are over the VCC, the
external trimming circuit should be added to reduce the voltage to obtain the input specification. The normal circuit and
trimming circuits are shown as follows:
+12V
Pull-up resister
4.7K Ohms
+12V
Pull-up resister < 1K
or totem-pole output
+12V
FAN Out
GND
10K
22K~30K
Fan Input
+12V
FANIN 1
FAN Out
GND
> 1K
Fan Input
FANIN 1
F75373S
3.3V Zener
FAN
Connector
F75373S
Figure 5-5 Fan with Tach Pull-Up to +12V, or Totern-Pole
Output and Register Attenuator
Figure 5-6 Fan with Tach Pull-Up to +12V, or
Totem-Pole Putput and Zener Clamp
7
V0.25P
FINTEK [ FEATURE INTEGRATION TECHNOLOGY INC. ]
