Kontron KT965 Series - Manual (Page 47)

KT965 Family
KTD-00699-S Public User Manual Date: 2010-04-15 Page 47 of 90
4.12 Fan connectors , FAN_CPU and FAN_SYS.
The FAN_CPU is used for connection of the active cooler for the CPU.
The FAN_SYS can be used to power, control and monitor a fan for chassis ventilation etc.
The 4pin header supports connection of 3-pin FANs, but it is recommended to use the 4-pin type for
optimized FAN speed control. The 3- or 4-pin mode is controlled in the BIOS setup menu.
4-pin Mode:
PIN
Signal Type Ioh/Iol
Pull
U/D Note
1 CONTROL O - -
2 SENSE I - 4K7
3 +12 V PWR - -
4 GND PWR - -
Signal description:
Signal Description
CONTROL PWM signal for FAN speed control
SENSE Tacho signal from the fan for supervision. The signals shall be generated by an open
collector transistor or similar. On board is a pull-up resistor 4K7 to +12V. The signal has to
be pulses, typically 2 Hz per rotation.
12V +12V supply for fan. A maximum of 2000 mA can be supplied from this pin.
GND Power Supply GND signal
3-pin Mode:
PIN
Signal Type Ioh/Iol
Pull
U/D Note
- - - - -
2 SENSE I - 4K7
3 +12 V PWR - -
4 GND PWR - -
Signal description:
Signal Description
SENSE Tacho signal from the fan for supervision. The signals shall be generated by an open
collector transistor or similar. On board is a pull-up resistor 4K7 to +12V. The signal has to
be pulses, typically 2 Hz per rotation.
12V +12V supply for fan, can be turned on/off or modulated (PWM) by the chipset.
A maximum of 2000 mA can be supplied from this pin.
GND Power Supply GND signal