Abstract: A flyback power converter includes a controller, a high-end driving circuit, an active clamp switch, a main switch and a zero current detection circuit. The high-end driving circuit is coupled to the controller. The active clamp switch is coupled to the high-end driving circuit for driving the active clamp switch. The main switch is coupled to the controller. The zero current detection circuit is coupled to the controller. The main switch and the active clamp switch are arranged on the primary side of a transformer. The switching period of a gate of the active clamp switch and the switching period of a gate of the main switch are controlled in reverse phase to achieve zero voltage or zero current conversion.

Abstract: An acoustic wave element includes: a substrate; a bonding structure on the substrate; a support layer on the bonding structure; a first electrode including a lower surface on the support layer; a cavity positioned between the support layer and the first electrode and exposing a lower surface of the first electrode; a piezoelectric layer on the first electrode; and a second electrode on the piezoelectric layer, wherein at least one of the first electrode and the second electrode includes a first layer and a second layer that the first layer has a first acoustic impedance and a first electrical impedance, the second layer has a second acoustic impedance and a second electrical impedance, wherein the first acoustic impedance is higher than the second acoustic impedance, and the second electrical impedance is lower than the first electrical impedance.

Abstract: A flyback power converter includes a controller, a high-end driving circuit, an active clamp switch, a main switch and a zero current detection circuit. The high-end driving circuit is coupled to the controller. The active clamp switch is coupled to the high-end driving circuit for driving the active clamp switch. The main switch is coupled to the controller. The zero current detection circuit is coupled to the controller. The main switch and the active clamp switch are arranged on the primary side of a transformer. The switching period of a gate of the active clamp switch and the switching period of a gate of the main switch are controlled in reverse phase to achieve zero voltage or zero current conversion.

Abstract: A power conversion apparatus is provided. The power conversion apparatus receives an AC input power by an input side and includes a capacitor, an AC-to-DC conversion unit and a discharge unit. The capacitor is connected with the input side. The AC-to-DC conversion unit is coupled to the input side, and configured to convert the AC input power after receiving the AC input power to generate a DC output power. The discharge unit is coupled to the capacitor and has at least two switch elements. The discharge unit enables the at least two switch elements when supply of the AC input power is interrupted, such that one of a first discharge path and a second discharge path formed by the at least two switch elements is taken to discharge or drain the energy stored in the capacitor.

Abstract: A low power consumption bleeder circuit is disclosed, and it is coupled to an alternating-current (AC) power source, an input filtering capacitor, and a rectifying filter. The low power consumption bleeder circuit includes a first switch component, a second switch component, and a controller. The first switch component is coupled to a first input terminal of the AC power source and a first connection terminal of the rectifying filter. The second switch component is coupled to a second input terminal of the AC power source and the first connection terminal of the rectifying filter. When the AC power source is detected to be removed, the controller controls at least one of the first switch component and the second switch component to be conductive.

Abstract: A conversion control circuit for controlling the operation of a power transistor is disclosed. The conversion control circuit includes a voltage-regulating switch and a control unit. One end of the voltage-regulating switch connects to an external voltage input terminal while another end connects to a voltage-regulating capacitor. The conversion control circuit converts an input voltage inputted from the external voltage input terminal into a power voltage. The power voltage is for supplying operating power to the conversion control circuit. The control unit receives a feedback voltage signal to generate a voltage-regulating pulse signal and a turn-on pulse signal, which are used for controlling the operations of the voltage-regulating switch and the power transistor, respectively and for defining a charging period for charging the voltage-regulating capacitor. A converter including the described conversion control circuit is also disclosed.

Abstract: A power conversion apparatus is provided. The power conversion apparatus receives an AC input power by an input side and includes a capacitor, an AC-to-DC conversion unit and a discharge unit. The capacitor is connected with the input side. The AC-to-DC conversion unit is coupled to the input side, and configured to convert the AC input power after receiving the AC input power to generate a DC output power. The discharge unit is coupled to the capacitor and has at least two switch elements. The discharge unit enables the at least two switch elements when supply of the AC input power is interrupted, such that one of a first discharge path and a second discharge path formed by the at least two switch elements is taken to discharge or drain the energy stored in the capacitor.

Abstract: A low power consumption bleeder circuit is disclosed, and it is coupled to an alternating-current (AC) power source, an input filtering capacitor, and a rectifying filter. The low power consumption bleeder circuit includes a first switch component, a second switch component, and a controller. The first switch component is coupled to a first input terminal of the AC power source and a first connection terminal of the rectifying filter. The second switch component is coupled to a second input terminal of the AC power source and the first connection terminal of the rectifying filter. When the AC power source is detected to be removed, the controller controls at least one of the first switch component and the second switch component to be conductive.

Abstract: A multiphase DC-to-DC converter is disclosed herein, which includes at least one DC-to-DC converting module. Each DC-to-DC converting module at least includes a first output inductor, a second output inductor and a current detector. The current detector is configured for detecting currents pass through the first output inductor and second output inductor. The current detector includes a first resistance, a second resistance, a first capacitor, a second capacitor, and a third resistance. The third resistance is directly or indirectly coupled between the first capacitor and a load circuit, and directly or indirectly coupled between the second capacitor and the load circuit, such that when the first capacitor is charged, a portion of the current charging the first capacitor passes through the second capacitor.

Abstract: A low power consumption bleeder circuit is disclosed, and it is coupled to an alternating-current (AC) power source, an input filtering capacitor, and a rectifying filter. The low power consumption bleeder circuit includes a first switch component, a second switch component, and a controller. The first switch component is coupled to a first input terminal of the AC power source and a first connection terminal of the rectifying filter. The second switch component is coupled to a second input terminal of the AC power source and the first connection terminal of the rectifying filter. When the AC power source is detected to be removed, the controller controls at least one of the first switch component and the second switch component to be conductive.

Abstract: A secondary side synchronous rectification control circuit is disclosed. The control circuit includes an inverted amplifier, a first comparator, and a driving unit. The inverted amplifier has an input end for receiving a drain source voltage signal from a synchronous rectification transistor and outputting an inverted amplification signal. The first comparator receives the inverted amplification signal and a first reference voltage for outputting a first comparison signal. The driving unit receives the first comparison signal and generates a driving signal according to the first comparison signal, for controlling the conduction status of the synchronous rectification transistor. The drain source voltage of the synchronous rectification transistor in the present invention is inverted amplified by an inverted amplifier, and it is connected to a comparator for generating the driving signal. The errors and defects of the turn-off timing of the driving signal may be solved and eliminated.

Abstract: A low power consumption bleeder circuit is disclosed, and it is coupled to an alternating-current (AC) power source, an input filtering capacitor, and a rectifying filter. The low power consumption bleeder circuit includes a first switch component, a second switch component, and a controller. The first switch component is coupled to a first input terminal of the AC power source and a first connection terminal of the rectifying filter. The second switch component is coupled to a second input terminal of the AC power source and the first connection terminal of the rectifying filter. When the AC power source is detected to be removed, the controller controls at least one of the first switch component and the second switch component to be conductive.

Abstract: A flyback power converter with multiple outputs is disclosed. The flyback power converter has a transformer, a first output circuit, a second output circuit, and a secondary side synchronous rectification controller. The transformer has a primary side winding, a first output winding, and a second output winding. The first output circuit has a first output capacitor for storing electric energy from the first output winding. The second output circuit has a second rectifying switch and a second output capacitor. The second output capacitor is utilized for storing the electric energy from the second output winding. The secondary side synchronous rectification controller controls the conduction time of the second rectifying switch according to a detecting signal of a secondary-side conduction period. The electric energy in the first output capacitor may be transferred to the second output capacitor through the second output winding and the second rectifying switch and vice versa.

Abstract: A multiphase DC-to-DC converter is disclosed herein, which includes at least one DC-to-DC converting module. Each DC-to-DC converting module at least includes a first output inductor, a second output inductor and a current detector. The current detector is configured for detecting currents pass through the first output inductor and second output inductor. The current detector includes a first resistance, a second resistance, a first capacitor, a second capacitor, and a third resistance. The third resistance is directly or indirectly coupled between the first capacitor and a load circuit, and directly or indirectly coupled between the second capacitor and the load circuit, such that when the first capacitor is charged, a portion of the current charging the first capacitor passes through the second capacitor.

Abstract: A predictive synchronous rectification controller for controlling at least one synchronous rectification switch is provided. The synchronous rectification controller has a ramp generator, a peak sampling unit, and an output control unit. The ramp generator receives a synchronous signal and generates a ramp signal accordingly. The peak sampling unit generates a predicted reference voltage signal by retrieving a peak voltage of the ramp signal. The output control unit compares the ramp signal with the predicted reference voltage signal to generate a synchronous rectification control signal to control a conducting state of the switch.

Abstract: A power factor correction (PFC) controller for controlling at least a switching unit is provided. The PFC controller has a feedback control circuit, a conductive current detecting circuit, and a switching control circuit. The feedback control circuit generates a feedback control signal for turning off the switch according to a feedback voltage signal. The conductive current detecting circuit has a clamp circuit, which generates a clamped signal restricted in a positive potential varying range according to a negative potential portion of a conductive-current detecting signal, and generates a cutoff signal for turning off the switch according to at least the clamped signal. The switching control circuit is utilized for controlling the switch according to the feedback control signal and the cutoff signal.

Abstract: A conversion control circuit for controlling the operation of a power transistor is disclosed. The conversion control circuit includes a voltage-regulating switch and a control unit. One end of the voltage-regulating switch connects to an external voltage input terminal while another end connects to a voltage-regulating capacitor. The conversion control circuit converts an input voltage inputted from the external voltage input terminal into a power voltage. The power voltage is for supplying operating power to the conversion control circuit. The control unit receives a feedback voltage signal to generate a voltage-regulating pulse signal and a turn-on pulse signal, which are used for controlling the operations of the voltage-regulating switch and the power transistor, respectively and for defining a charging period for charging the voltage-regulating capacitor. A converter including the described conversion control circuit is also disclosed.

Abstract: A secondary side synchronous rectification control circuit is disclosed. The control circuit includes an inverted amplifier, a first comparator, and a driving unit. The inverted amplifier has an input end for receiving a drain source voltage signal from a synchronous rectification transistor and outputting an inverted amplification signal. The first comparator receives the inverted amplification signal and a first reference voltage for outputting a first comparison signal. The driving unit receives the first comparison signal and generates a driving signal according to the first comparison signal, for controlling the conduction status of the synchronous rectification transistor. The drain source voltage of the synchronous rectification transistor in the present invention is inverted amplified by an inverted amplifier, and it is connected to a comparator for generating the driving signal. The errors and defects of the turn-off timing of the driving signal may be solved and eliminated.

Abstract: A flyback power converter with multiple outputs has a transformer, a low-voltage output circuit, a high-voltage output circuit, and a secondary side post regulator circuit is provided. The transformer has a first secondary winding and a second secondary winding. The low-voltage output circuit has a low-voltage output capacitor and a rectifier unit, and is coupled to the first secondary winding to generate a low voltage output. The high-voltage output circuit has a high-voltage output switch and a high-voltage output capacitor, and is coupled to the second secondary winding to generate a high voltage output. The secondary side post regulator circuit adjusts on-time of the high-voltage output switch according to a feedback signal to have the energy stored in the high-voltage capacitor transmitted to the low-voltage capacitor to lower down the voltage level of the high output voltage.

Abstract: A predictive synchronous rectification controller for controlling at least one synchronous rectification switch is provided. The synchronous rectification controller has a ramp generator, a peak sampling unit, and an output control unit. The ramp generator receives a synchronous signal and generates a ramp signal accordingly. The peak sampling unit generates a predicted reference voltage signal by retrieving a peak voltage of the ramp signal. The output control unit compares the ramp signal with the predicted reference voltage signal to generate a synchronous rectification control signal to control a conducting state of the switch.