| 摘要 |
A brushless DC fan driver is disclosed, which includes an amplifier, a pulse generator and a driving unit for rotating a fan, and further includes a tachometer unit, a lock protection unit and an overshoot voltage prevention unit for providing a reliable driving capability. The tachometer unit is provided to present a signal representing the rotation speed of the fan based on an amplified alternative polarity signal from a Hall sensor in the fan. The lock protection unit is provided to detect that the fan is locked up based on the amplified alternative polarity signal thereby generating a lock signal to shut down the fan driver and a restart signal to attempt to restart the locked fan. The overshoot voltage prevention unit is connected to the driving unit for detecting and bypassing overshoot voltages generated by the fan in operation.
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