Abstract: A switching power supply circuit can include: a high-frequency switch network configured to generate a high-frequency AC signal by performing high-frequency chopping on a low-frequency AC input signal; a transformer configured to receive the high-frequency AC signal at a primary winding thereof, to perform a voltage conversion on the high-frequency AC signal, and to generate an output signal at a secondary winding of the transformer; and a rectifier module configured to generate a DC signal by rectifying the output signal at the secondary winding of the transformer.

Abstract: A frequency modulation circuit can include: a modulation circuit configured to generate a digital modulation signal and an analog modulation signal according to an input signal of the frequency modulation circuit; and a phase-locked loop having a voltage-controlled oscillator configured to receive a reference frequency, and to modulate a frequency of an output signal of the voltage-controlled oscillator according to the analog modulation signal and the digital modulation signal.

Abstract: A capacitor management circuit for a power management circuit, where the power management circuit includes a bidirectional converter having first and second ports, the capacitor management circuit includes a plurality of capacitor modules, and where each capacitor module includes: a switch and a capacitor coupled in series between two terminals of the second port; and a control circuit configured to detect state information of the corresponding capacitor, and to control operation state of the switch, in order to realize independent control of each capacitor.

Abstract: A switching control circuit for a flyback converter having a main switch coupled to a primary winding of a transformer and a rectifier switch coupled to a secondary winding of the transformer, can include: a first voltage generating circuit configured to generate a first voltage sampling signal representing information of an input voltage; a synchronous rectification control circuit configured to adjust an on-time of the rectifier switch according to the first voltage sampling signal in order to adjust an absolute value of a negative current flowing through the secondary winding; and where the negative current is configured to discharge a parasitic capacitor of the main switch in order to reduce a drain-source voltage of the main switch.

Abstract: A converter can include: (i) a first switch having a first terminal for receiving an input voltage, and a second terminal coupled to a first terminal of a second switch; (ii) an inductor having a first terminal coupled to a common node of the first and second switches, and a second terminal coupled to a first terminal of a third switch, where second terminals of the second and third switches are coupled to ground; and (iii) a plurality of output channels coupled to a common node of the inductor and the third switch, where the converter operates in a buck-boost mode, a buck mode, or a boost mode based on the relationship between the input voltage and output voltages of the plurality of output channels.

Abstract: A semiconductor structure can include: a semiconductor substrate having a first region, a second region, and an isolation region disposed between the first region and the second region; an isolation component located in the isolation region; and where the isolation component is configured to recombine first carriers flowing from the first region toward the second region, and to extract second carriers flowing from the second region toward the first region.

Abstract: A method of forming a lead frame can include: providing a frame base; providing a substrate to support the frame base; and selectively etching the frame base to form first and second type pins. The first type pins are distributed in the central area of the lead frame, and the second type of the pins are distributed in the edge area of the lead frame. The first type pins are separated from the second type of the pins, and the first and second type pins are not connected by connecting bars. A pattern of a first surface of the first and second type pins is different from that of a second surface of the first and second type pins. The metal of the first surface is different from the metal of the second surface, and the second surface is opposite to the first surface.

Abstract: A leakage protection circuit can include: a pull-down current generation circuit coupled between output terminals of a rectifier circuit; and a control circuit configured to control the pull-down current generation circuit to generate a pull-down current during a predetermined time interval, and to determine whether leakage occurs in accordance with a voltage detection signal that is representative of an output voltage of the rectifier circuit.

Abstract: A control circuit for a switching converter having a main power switch and a freewheeling circuit, can be configured to: control the freewheeling circuit to be turned on in a first time interval after the main power switch is turned off; control the freewheeling circuit to be turned on in a second time interval after the first time interval, in order to reduce turn-on loss of the main power switch; and where the first time interval and the second time interval do not overlap each other in a switching cycle.

Abstract: A current source circuit and an LED driving circuit applying the same. A current at an output terminal of an operational transconductance amplifier is shunted based on a first control signal that includes duty cycle information, or an input signal at at least one input terminal of the operational transconductance amplifier is controlled to be switched between different voltage signals based on the first control signal, so as to adjust an output current of a current adjustment circuit. A driving voltage for driving a current generation circuit is adjusted based on the output current. Thereby, a driving current generated by the current source circuit is correlated with the duty cycle information. An amplitude modulation circuit used, a low-pass filter and the like for processing the first control signal are not used, effectively simplifying circuit design and improving system efficiency.

Abstract: A power converter can include an input circuit having a primary winding and a primary power switch coupled in series between an input terminal and the ground; a first output circuit having a first secondary winding which is coupled with the primary winding; a second output circuit having a second secondary winding coupled with the primary winding and at least one secondary power switch; a first control circuit that controls the primary power switch to be turned on and off to adjust an output signal of the first output circuit; and a second control circuit which controls the secondary power switch to be turned on and off to adjust an output signal of the second output circuit. The secondary power switch can be turned on before the primary power switch is turned off in a first state in one switching cycle, in order to reduce the switching interference.

Abstract: A ripple voltage control circuit for controlling a switching converter, including: a control circuit configured to superimpose a compensation voltage and a ripple voltage on a feedback voltage that represents an output voltage of the switching converter, in order to generate a ripple signal; the control circuit being configured to superimpose a bias voltage on a reference voltage that represents a desired output voltage of the switching converter as a reference signal, and to compare the ripple signal against the reference signal in order to generate a turn-on signal for a main power switch of the switching converter; and where the compensation voltage adaptively varies with a duty cycle of the main power switch, such that the ripple signal is independent of the duty cycle, in order to maintain the feedback voltage as equal to the reference voltage.

Abstract: A dimming mode detection circuit for an LED lighting system that receives an alternating current input voltage and generates a bus voltage to drive an LED load, the dimming mode detection circuit including: a leading edge detection circuit configured to generate a leading edge detection signal by detecting a leading edge of a first voltage representative of the bus voltage in one sine half-wave cycle, in order to determine whether the LED lighting system operates in a leading edge dimming mode; and a trailing edge detection circuit configured to generate a trailing edge detection signal in accordance with a time length of a first interval from a first value of the first voltage in a previous sine half-wave cycle to a second value of the first voltage in a next sine half-wave cycle, in order to determine whether the LED lighting system operates in a trailing edge dimming mode.

Abstract: A power converter can include: a rectifier circuit; a silicon controlled dimmer coupled between an AC input terminal and an input terminal of the rectifier circuit; and a bleeder circuit coupled to an output terminal of the rectifier circuit, and being configured to provide a bleeder current after the silicon controlled dimmer is turned off. A method of controlling a power converter, can include: generating a bleeder current flowing though output terminals of a rectifier circuit of the power converter after a silicon controlled dimmer is turned off; and where the silicon controlled dimmer coupled to the rectifier circuit receives an AC input voltage.

Abstract: A power converter can include: an input circuit, including a primary winding and a primary power switch which are coupled in series between an input terminal and a first ground; at least one constant voltage output circuit, including a first secondary winding coupled with said primary winding; and at least one constant current output circuit, including a second secondary winding coupled with said primary winding, a secondary power switch, a current output port, a second rectifier circuit and a current sampling circuit. The second rectifier circuit can be coupled between the current output port and the second secondary winding, the current output port can be coupled to an LED as a load, the LED may be coupled between one end of the second secondary winding and a second ground, and the secondary power switch and the current sampling circuit can connect in series.

Abstract: A control circuit for controlling a power converter can include: a constant voltage output module, a constant current output module, and a power stage circuit; and where the control circuit is configured to select one of a first feedback signal representative of output information of the constant current output module, and a second feedback signal representative of output information of the constant voltage output module as a feedback input signal based on operation states of the constant current output module and the constant voltage output module, in order to control a switching state of a power switch of the power stage circuit.

Abstract: An apparatus for an LED driver with a silicon-controlled dimmer, can include: a bleeder circuit coupled to a DC bus of the LED driver; and a controller configured to control the bleeder circuit to draw a bleeder current from the DC bus when a conduction angle of the silicon-controlled dimmer is less than an angle threshold, in order to maintain a conduction state of the silicon-controlled dimmer.

Abstract: An LED drive circuit can include: a transistor and an LED load coupled in series, and being configured to receive a direct current bus voltage, and to generate an input current; and a control circuit configured to generate a drive signal to control an operation state of the transistor to control a distribution range of the input current by controlling an amount of accumulated charge of the input current during a half power frequency period.

Abstract: An apparatus including: a switching converter having a main switch configured to provide power to a transformer, an auxiliary switch configured to provide a release path for leakage inductance energy of the transformer, and a clamp capacitor coupled in series with the auxiliary switch; and a control circuit configured to control the main switch to be off and the auxiliary switch to operate to discharge the clamp capacitor when in an over-voltage protection mode. A method of controlling the switching converter can include: controlling the main switch to be off; and controlling the auxiliary switch to operate to discharge the clamp capacitor when in an over-voltage protection mode.

Abstract: A resonant switching converter can include: a voltage switching circuit configured to receive a first input voltage, and to generate a second input voltage of a resonant branch coupled to the voltage switching circuit; where when the voltage switching circuit is in a first operating state, the second input voltage provided to the resonant branch is less than the first input voltage; and where when the voltage switching circuit is in a second operating state, the input voltage provided to the resonant branch is zero.