Abstract: A voltage converter controller, adapted to a voltage converter circuit, includes a power switch controller and a dead-time determining circuit. The power switch controller receives a PWM signal and outputs a high-side control signal and a low-side control signal accordingly to control the conduction and cut-off of a high-side power switch and a low-side power switch respectively. When the power switch controller starts to control the low-side power switch cut-off, after a first dead-time, the power switch controller starts to control the high-side power switch conducting. The dead-time determining circuit detects a current of the low-side power switch to be larger or smaller than a threshold current when the low-side power switch is conducted, and determines the first dead-time to be a first value or a second value accordingly.

Abstract: A voltage converter controller, adapted to a voltage converter circuit, includes a power switch controller and a dead-time determining circuit. The power switch controller receives a PWM signal and outputs a high-side control signal and a low-side control signal accordingly to control the conduction and cut-off of a high-side power switch and a low-side power switch respectively. When the power switch controller starts to control the low-side power switch cut-off, after a first dead-time, the power switch controller starts to control the high-side power switch conducting. The dead-time determining circuit detects a current of the low-side power switch to be larger or smaller than a threshold current when the low-side power switch is conducted, and determines the first dead-time to be a first value or a second value accordingly.

Abstract: A control circuit of a LED driver utilizes a counter to acquire a cycle and a conduction time or a non-conduction time of an AC phase-cut voltage outputted by a TRIAC dimmer. A bleeding signal is determined according to the cycle and the conduction time or the non-conduction time and used for adjusting a bleeding current so as to avoid a flickering of the LED. The control circuit does not need extra pins for coupling a large capacitor, but the bleeding signal can be still acquired. Preferably, the present invention is suitable for an IC of low pin numbers.

Abstract: A method for reading/writing a chip in a USB type-C cable comprises converting a read/write command into unstructured vendor defined message (UVDM) that is conforming to a USB power delivery specification. Such UVDM will be delivered to the chip via a type-C configuration channel interface. The chip analyzes the UVDM to acquire the read/write command and reads or modifies the content of a non-volatile memory in the chip according to the read/write command. Due to use of the type-C configuration channel interface, which is inherent in the USB type-C cable, to read/write the chip, it needs no extra interface which otherwise increases costs.

Abstract: A feedback signal stabilized by a capacitor and related to an output voltage of a power converter is used to acquire the output power information of the power converter, and a control circuit uses a second clock not related to the switching frequency of the power converter to count a duration time of the feedback signal being higher than a threshold. When the duration time is higher than a preset time, an abnormal output power of the power converter is distinguished and the power converter will be turned off. The feedback signal will not vary severely even if the output terminal of the power converter is interfered, and the counted duration time will not be influenced when the switching frequency is changing caused by a load changing.

Abstract: A linear LED driver comprises a transistor having an input terminal coupled to a LED. When the transistor is turned on, the LED is lighted. The linear LED driver further includes a protection circuit for judging whether an instant high voltage variation occurs or not according to at least one of the voltages of a control terminal and an output terminal of the transistor so as to achieve a protection function.

Abstract: A soft-start switching power converter includes a voltage converting circuit and a soft-start circuit. The voltage converting circuit includes a transformer, and a first switch which includes a first terminal connected to the transformer, a second terminal providing a trigger signal, and a control terminal receiving a control signal, and which is controlled to switch between conduction and nonconduction, such that the transformer generates a feedback voltage. The soft-start circuit receives the trigger signal, generates the control signal according to the trigger signal, and determines whether or not to clamp the control signal at a preset voltage level based on the trigger signal.

Abstract: A control chip of a driving circuit for driving a LED array shares a ground terminal with the LED array so that, without an additional winding, the driving circuit can provide a supply voltage for the control chip, implement a zero-current switching function, and implement an over-voltage protection function. Since no additional windings are needed, the related costs and the size of the driving circuit are decreased.

Abstract: A temperature detecting circuit and method thereof, adapted to a voltage converter circuit which includes a current detecting circuit having a detecting output port outputting a current detecting signal proportional to an output current of the voltage converter circuit, includes: a current signal processing unit, having a signal input port coupling to the detecting output port, a first detecting output port generating a first processing signal with a first temperature coefficient, a second detecting output port generating a second processing signal with a second temperature coefficient, wherein the first and the second processing signals are proportional to the current detecting signal; and, a temperature calculating unit, receiving the first and the second processing signals and performing calculation to derive a temperature value.

Abstract: A frequency jittering control circuit for a PFM power supply includes a pulse frequency modulator to generate a frequency jittering control signal to switch a power switch to generate an output voltage. The frequency jittering control circuit jitters an input signal or an on-time or off-time of the pulse frequency modulator to jitter the switching frequency of the power switch to thereby improve EMI issue.

Abstract: A linear LED driver includes a voltage supply terminal providing a driving voltage, at least one first transistor, each of which has an input terminal coupled to a respective LED, and a bleeder circuit. When the voltage of the output terminal of each of the at least one first transistor is lower than a first threshold and a power voltage is higher than a second threshold, the bleeder circuit will generate a bleeder current to discharge the voltage supply terminal so as to prevent the LEDs from flickering. The bleeder circuit detects the voltage of the output terminal of each of the at least one first transistor. Therefore, whether the LEDs are lighted up can be confirmed so that the bleeder current can be provided at properly time point.

Abstract: An over-voltage protection circuit is applied to a switching voltage converting circuit. The switching voltage converting circuit manipulates an upper bridge power switch in the circuit, so as to convert an input voltage into an output voltage by an inductor. A channel of the upper bridge power switch and the inductor are coupled to a phase end. The over-voltage protection circuit includes: a comparator, coupled to the switching voltage converting circuit, wherein when a voltage of the phase end is higher than a voltage limiting threshold, an output end of the comparator outputs a first voltage level; and a pulse width detection unit, coupled to the output end of the comparator, wherein when the output end of the comparator remains the first voltage level for a time period longer than a protection period, the pulse width detection unit outputs an over-voltage protection activation signal.

Abstract: A control circuit and method for an audio amplifier detect a signal for driving a speaker to control the switching frequency and the operation mode of a charge pump in the audio amplifier, to improve power efficiency of the audio amplifier. Preferably, a digital interface is further used to test the magnitude of the output signal of the audio amplifier, to reduce the costs of analog test. The charge pump has fewer switches and thus saves costs and die area of an integrated circuit. The control method needs only two phase control for the charge pump to generate a positive voltage and a negative voltage, and thus simplifies the operation of the circuit.

Abstract: A voltage converting controller. When output current increases from a first current value to a second current value, the voltage converting controller temporarily sets a control frequency to a maximum frequency value. After a period of time, the voltage converting controller sets the control frequency to a target control frequency corresponding to the second current value. And, when the output current increases from the first current value to the second current value, the voltage converting controller temporarily sets a secondary-side output voltage to an transient output value; and after a period of time, the voltage converting controller sets a steady state value of the secondary-side output voltage to an output voltage steady state value corresponding to the second current value.

Abstract: A voltage converting controller is applied to a switching voltage converting circuit, in which the voltage converting controller periodically operates a high-side power switch and a low-side power switch in the switching voltage converting circuit with a high-side control signal and a low-side control signal, respectively, so as to convert an input voltage into an output voltage via an inductor. Defining an ideal duty cycle as the rating value of the output voltage divided by the value of the input voltage, when the ideal duty cycle is less than one threshold duty cycle, then the period of the high-side control signal is a constant; and when the ideal duty cycle is greater than the threshold duty cycle, the period of the high-side control signal and the period of the ideal duty cycle are positively correlated.

Abstract: A voltage converting controller, in which when an output current increases from a first current value to a second current value, the voltage converting controller temporarily sets a control frequency to a maximum frequency value; and after a period of time, sets the control frequency to a target control frequency corresponding to the second current value. In addition, when the output current increases from the first current value to the second current value, the voltage converting controller temporarily sets a secondary-side output voltage to an transient output value; and after a period of time, sets a steady state value of the secondary-side output voltage to an output voltage steady state value corresponding to the second current value.

Abstract: A method and device for detecting a force factor of a loudspeaker is provided. The method includes the steps of: providing the loudspeaker with a dynamic driving voltage signal; continuously measuring a current signal flowing through the loudspeaker; observing the current signal and if the current signal shows that the diaphragm excursion of the loudspeaker is greater than an displacement limit, decreasing the driving voltage signal until the current signal shows that the diaphragm excursion of the loudspeaker is less than or equal to the displacement limit; and substituting the current driving voltage signal, the current signal, the displacement limit, and an electrical impedance of the loudspeaker into a function so as to compute the force factor of the loudspeaker.

Abstract: A power converter includes a rectifier and a power factor corrector. The rectifier is to be coupled to an alternating current power source and is configured to output a rectified signal. The power factor corrector includes a correcting circuit and a control circuit. The correcting circuit receives the rectified signal and is configured to generate an output voltage based on the rectified signal and a driving signal. The control circuit is configured to generate a first to-be-compared signal based on the rectified signal, to generate a second to-be-compared signal based on the output voltage, to compare the first and second to-be-compared signals, and to generate the driving signal based on a result of comparison performed thereby.

Abstract: A light emitting system includes a series connection of a light emitting unit and a variable current source, and a voltage conversion device that includes a rectifier circuit and an output circuit. The rectifier circuit rectifies an AC voltage to generate a rectified voltage across a first rectifier output coupled to one end of the series connection of the light emitting unit and the variable current source, and a second rectifier output. The output circuit is coupled between the second rectifier output and another end of the series connection of the light emitting unit and the variable current source, and is configured to generate a direct-current (DC) output voltage.

Abstract: A wireless power receiver includes a power receiving circuit wirelessly receiving power transmitted from a wireless power transmitter so as to generate an induced current, and a rectifying-and-modulating circuit including first to eighth switches and a control unit. The control unit is operable to control operation of each of the first to eighth switches between conduction and non-conduction. Accordingly, the first to fourth switches cooperatively constitute a full-bridge rectifier for rectifying the induced current generated by the power receiving circuit, and each of the fifth to eighth switches is operable to switch synchronously with a respective one of the first to fourth switches or to became non-conducting, thereby changing an amplitude of the induced current.