A secondary side controller of a flyback AC-DC converter includes an integrated circuit, which includes: an analog-to-digital converter (ADC) coupled to a voltage bus (VBUS), the ADC to output a digital value corresponding to a voltage level of the VBUS; first logic configured to generate a reference voltage based on the digital value; second logic configured to generate a VBUS gain value based on output power of a flyback transformer of the flyback AC-DC converter; an integrator to accumulate current corresponding to a sensed voltage at a drain of a synchronous rectifier (SR) of a secondary side of the flyback transformer, the accumulated current to be modified according to the VBUS gain value, wherein the integrator outputs an updated sensed voltage; and a comparator to output a detection signal, indicative of a negative sense voltage, in response to the updated sensed voltage matching the reference voltage.

Systems and methods for power conversion are described. For example, a system may include a transformer including a plurality of secondary windings; a first set of switches connecting respective taps of the plurality of secondary windings to a first terminal; a second set of switches connecting the respective taps of the plurality of secondary windings to a second terminal; and an electrical load connected between the first terminal and the second terminal.

A switching bridge for the DC-DC stage of a power converter, the switching bridge having one or more sets of upper and lower series-connected switches (S1, S2) connected across a DC bus and arranged to be switched to provide an output AC voltage, the switching bridge further comprising a voltage divider (C1) arranged to vary the output AC voltage level according to the switching state of the switches.

An example a circuit for controlling a power converter comprises a first power domain circuit including a first control circuit and a first driver circuit, wherein the first control circuit controls the first driver circuit to drive a first semiconductor device, wherein a second power domain circuit includes a second control circuit and a second driver circuit. The first control circuit is configured to receive a control signal for controlling the second driver circuit to drive a second semiconductor device; and identify, based on the control signal, a future electrical characteristic of a second power domain output of the power converter. Additionally, the first control circuit is configured to determine, based on the future electrical characteristic of the second power domain output of the power converter, whether to adjust one or more control parameters for controlling the first driver circuit to drive the first semiconductor device.

A switching power supply circuit (100XA) includes switching elements (SW31 and SW41), a detector (310) configured to detect a physical quantity (Tout) related to the output power of the switching power supply circuit, and a variable controller (42) configured to variably control the gate driving voltages (G3 and G4) for the switching elements based on the result (Idet) of detection by the detector.

A synchronous rectification control circuit has a turn-on detection circuit. The turn-on detection circuit has a slope detection circuit and a threshold generation circuit. The slope detection circuit generates a slope representation signal representing a falling slope of the detection signal. The threshold generation circuit generates a threshold signal by selecting one of threshold reference signals according to a driving signal. The turn-on detection circuit generates a comparison result signal by comparing the slope representation signal and the threshold signal for controlling the switch state of the synchronous rectification transistor.

Methods, apparatus, systems, and articles of manufacture for zero voltage switching of flyback converters are disclosed. An example apparatus includes a first driver to operate a first switch to direct a first current to flow to a first winding of a transformer, and a second driver to operate a second switch to direct a second current to flow to a second winding of the transformer and operate the second switch to cause the second current to discharge a voltage of the first switch.

A power conversion apparatus includes: a first power terminal; a switching circuit including a first switching device on a path coupling a first power node to a first node, a second switching device on a path coupling the first node to a second power node, a third switching device on a path coupling the first power node to a second node, and a fourth switching device on a path coupling the second node to the second power node; a transformer including a first winding coupled to the switching circuit and a second winding; a rectifier circuit; a second power terminal; and a controller that controls operations of the switching circuit and the rectifier circuit to supply power from the second power terminal toward the first power terminal during a predetermined period different from a period during which power is supplied from the first power terminal toward the second power terminal.

A switching mode power supply with zero voltage switching is discussed. It adopts a primary control circuit to turn on a primary switch circuit when a current flowing through the primary switch circuit reaches an inverse current threshold or when a variation rate of a voltage signal indicative of a voltage across the primary switch circuit reaches a rate threshold.

A startup circuit adapted to be coupled to an input voltage supply and operable to supply an output voltage at an output terminal, the startup circuit including: a first transistor having a first control terminal, a first current terminal and a second current terminal, the first current terminal adapted to be coupled to the input voltage supply and the second current terminal coupled to the output terminal; a precharge circuit having a first terminal, a second terminal and a third terminal, the second terminal adapted to be coupled to the input voltage supply and the third terminal coupled to the first control terminal; a current limiter coupled to the precharge circuit, the first control terminal and the second current terminal; a second transistor having a second control terminal, a third current terminal and a fourth current terminal, the third current terminal coupled to the precharge circuit and the second control terminal adapted to be coupled to a control signal; and a third transistor having a third control terminal, a fifth current terminal and a sixth current terminal, the fifth current terminal coupled to the first control terminal and the third control terminal is adapted to be coupled to the control signal.