f75375 Feature Integration Technology Inc., f75375 Datasheet - Page 13

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

Monitor Temperature from thermo diode
Over Temperature Signal (OVT#)
The F75375S 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.
Fan
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:
Also, if the CPU, GPU or external circuits provide thermal diode for temperature monitor, F75375S is capable to these
situations. The build-in reference table is for PNP 2N3906, and each different kind of thermal diode should be matched with
specific offset and BJT gain. In the
to VREF (pin13).
Fintek
T
OVT#
HYST
To
Figure
5-3, the 2N3906 PNP is connected by a serial resistor with 20K ohm, then connect
Figure 5-4
7
Feature Integration Technology Inc.
F75375S/F75375SG
July 2007
V0.26P