Abstract: A driving circuit for driving a fan with a plurality of operational modes includes an initiation module for generating a switch signal according to a feedback signal, a control module coupled to the initiation module for utilizing a pulse frequency modulation technique to generate a control signal according to the switch signal and a predetermined comparison signal, so as to drive the fan for a rotational operation, and a feedback module coupled to the fan for generating the feedback signal according to a conduction result of the fan. The rotational operation includes the plurality of operational modes, and the fan is switched between the plurality of operational modes according to different conduction results of the fan.

Abstract: A driving circuit for driving a fan with a plurality of operational modes includes an initiation module for generating a switch signal according to a feedback signal, a control module coupled to the initiation module for utilizing a pulse frequency modulation technique to generate a control signal according to the switch signal and a predetermined comparison signal, so as to drive the fan for a rotational operation, and a feedback module coupled to the fan for generating the feedback signal according to a conduction result of the fan. The rotational operation includes the plurality of operational modes, and the fan is switched between the plurality of operational modes according to different conduction results of the fan.

Abstract: A driving circuit for a fan includes an initiation module for generating a switch signal according to a feedback signal, a control module coupled to the initiation module for generating a control signal according to the switch signal and a predetermined comparison signal, so as to drive the fan for a rotational operation, and a feedback module coupled to the fan for generating the feedback signal according to a conduction result of the fan, wherein the control module utilizes a pulse frequency modulation technique to generate the control signal, and the conduction result is realized via a voltage type or a current type to correspond to a rotational speed of the rotational operation.

Abstract: A method capable of sensing a heavy load and a short circuit of a low dropout regulator includes providing a ramp pulse signal to the low dropout regulator, providing a square waveform, comparing a feedback signal of the low dropout regulator with the square waveform, and determining the low dropout regulator is a heavy load or a short circuit if a duration that the feedback signal is greater than a low voltage level of the square waveform and lower than a high voltage level of the square waveform is not greater than a pulse width of the square waveform. The method includes determining the low dropout regulator is a light load if the duration that the feedback signal is greater than the low voltage level of the square waveform and lower than the high voltage level of the square waveform is greater than the pulse width of the square waveform.

Abstract: A method capable of sensing a heavy load and a short circuit of a low dropout regulator includes providing a ramp pulse signal to the low dropout regulator, providing a square waveform, comparing a feedback signal of the low dropout regulator with the square waveform, and determining the low dropout regulator is a heavy load or a short circuit if a duration that the feedback signal is greater than a low voltage level of the square waveform and lower than a high voltage level of the square waveform is not greater than a pulse width of the square waveform. The method includes determining the low dropout regulator is a light load if the duration that the feedback signal is greater than the low voltage level of the square waveform and lower than the high voltage level of the square waveform is greater than the pulse width of the square waveform.