Abstract: A zero-crossing detection circuit and a commutation device using the zero-crossing detection circuit are provided. The zero-crossing detection circuit is adapted into a three-phase brushless DC (direct current) motor with first to third coils. One terminal of each of the first to third coils is electrically coupled together with each other. The detection circuit comprises a first selection circuit, a second selection circuit and a comparator. The first selection circuit and the second selection circuit are both electrically coupled to another terminals of the first to third coils, to obtain first to third terminal voltages, and output one of the first to third terminal voltages according to a selection signal. The comparator is configured for comparing an output of the first selection circuit and an output of the second selection circuit, to output a comparing result.

Abstract: A zero-crossing detection circuit and a commutation device using the zero-crossing detection circuit are provided. The zero-crossing detection circuit is adapted into a three-phase brushless DC (direct current) motor with first to third coils. One terminal of each of the first to third coils is electrically coupled together with each other. The detection circuit comprises a first selection circuit, a second selection circuit and a comparator. The first selection circuit and the second selection circuit are both electrically coupled to another terminals of the first to third coils, to obtain first to third terminal voltages, and output one of the first to third terminal voltages according to a selection signal. The comparator is configured for comparing an output of the first selection circuit and an output of the second selection circuit, to output a comparing result.

Abstract: A pulse width modulation circuit capable of linearly adjusting duty cycle with voltage, which comprises an input voltage source for generating an input voltage, a regulator for generating a regulated voltage, a first voltage-dividing unit for providing a first divided voltage, a second voltage-dividing unit for providing a second divided voltage, a third voltage-dividing unit for providing a third divided voltage, a voltage adder for adding the first divided voltage and the third divided voltage for generating a high level voltage, a waveform generator for generating an oscillating signal according to the high level voltage and the third divided voltage, and a comparator having a first input terminal coupled to the second voltage-dividing unit, a second terminal coupled to the waveform generator, and an output terminal for comparing the second divided voltage with the oscillating signal to output a pulse width modulation signal through the output terminal.

Abstract: A pulse width modulation circuit capable of linearly adjusting duty cycle with voltage, which comprises an input voltage source for generating an input voltage, a regulator for generating a regulated voltage, a first voltage-dividing unit for providing a first divided voltage, a second voltage-dividing unit for providing a second divided voltage, a third voltage-dividing unit for providing a third divided voltage, a voltage adder for adding the first divided voltage and the third divided voltage for generating a high level voltage, a waveform generator for generating an oscillating signal according to the high level voltage and the third divided voltage, and a comparator having a first input terminal coupled to the second voltage-dividing unit, a second terminal coupled to the waveform generator, and an output terminal for comparing the second divided voltage with the oscillating signal to output a pulse width modulation signal through the output terminal.

Abstract: A driving circuit for switching DC power includes a DC power generator, a bridge circuit, a control signal generator, and a clamping module. The bridge circuit includes a plurality of legs each including an up-bridge switch and a down-bridge switch. The clamping circuit is coupled to each up-bridge switch of the bridge circuit for clamping voltage of an input end of the up-bridge switch.

Abstract: A power cutter, an oscillator, a counter, a S-R latch, and a Hall bias are further disposed inside a DC motor driving circuit so that current consumption of the DC motor driving circuit is reduced significantly under a standby mode. When the counter detects that a received pulse width modulation signal stays at a low electrical level over a predetermined time, the counter triggers the S-R latch so as to activate a disabling signal of the power cutter for shutting down most elements until the pulse width modulation signal returns to a high electrical level. With the aid of the built-in Hall bias, space for externally coupling the Hall bias is saved, and moreover, a Hall sensor retrieves a dynamically-adjusted power and currents so that remarkable current consumption is saved under a standby mode.

Abstract: A power cutter, an oscillator, a counter, a S-R latch, and a Hall bias are further disposed inside a DC motor driving circuit so that current consumption of the DC motor driving circuit is reduced significantly under a standby mode. When the counter detects that a received pulse width modulation signal stays at a low electrical level over a predetermined time, the counter triggers the S-R latch so as to activate a disabling signal of the power cutter for shutting down most elements until the pulse width modulation signal returns to a high electrical level. With the aid of the built-in Hall bias, space for externally coupling the Hall bias is saved, and moreover, a Hall sensor retrieves a dynamically-adjusted power and currents so that remarkable current consumption is saved under a standby mode.

Abstract: A driving circuit for switching DC power includes a DC power generator, a bridge circuit, a control signal generator, and a clamping module. The bridge circuit includes a plurality of legs each including an up-bridge switch and a down-bridge switch. The clamping circuit is coupled to each up-bridge switch of the bridge circuit for clamping voltage of an input end of the up-bridge switch.