Low-pin count fan speed control system and a method thereof

A low-pin count fan speed control system which is a chip to control operation of the fan, the chip comprising:

• an activation unit, which provides a pre-determined voltage and drives a fan to rotate;
• an idle speed regulation unit, which is connected with the activation unit and limits the fan to slow down to a pre-determined rotation speed after the fan starts completely;
• temperature transition unit, which increases the fan speed when the fan slows down to the pre-determined rotation speed and a temperature reaches to a pre-determined temperature;
• a positive temperature regulation slope unit, which properly increases the rotation speed in proportional to the temperature when the fan is accelerating, with the fan achieving a full speed upon operating to a condition that the temperature reaches a pre-determined temperature;
• and
• an over-temperature protection unit, which is activated when the fan is operating at the full speed and the temperature rises to a pre-determined temperature.