An embodiment converter includes a magnetic material, a first circuit including a first winding surrounding the magnetic material and a clamp circuit configured to reset a power conversion operation, the first circuit being configured to convert power received from a first input voltage source to provide the converted power to a load, and a second circuit including a second winding surrounding the magnetic material, the second circuit being configured to convert power received from a second input voltage source to provide the converted power to the load and to perform the power conversion operation being reset by the clamp circuit.

A switching regulator includes a first switch circuit, a second switch circuit, and a protection circuit. The first switch circuit has a first connection node coupled to a first reference voltage, and a second connection node coupled to one end of an inductor. The second switch circuit has a first connection node coupled to a second reference voltage, and a second connection node coupled to the one end of the inductor. The protection circuit senses a voltage level at the first connection node of the first switch circuit, and selectively enables an auxiliary current path in response to the voltage level at the first connection node of the first switch circuit, wherein the auxiliary current path and at least the first switch circuit are arranged in a parallel connection fashion.

In an embodiment, a method for operating an ACF converter includes: turning on a low-side transistor that is coupled between a primary winding of a transformer and a reference terminal to cause a forward current to enter the primary winding, turning off the low-side transistor; after turning off the low-side transistor, turning on a high-side transistor that is coupled between the primary winding and a clamp capacitor to cause a reverse current to flow through the primary winding; and after turning on the high-side transistor, when an overcurrent of the reverse current is not detected, keeping the high-side transistor on for a first period of time, and turning off the high-side transistor after the first period of time, and when the overcurrent of the reverse current is detected, turning off the high-side transistor without keeping the high-side transistor on for the first period of time.

A regenerative gate charging circuit includes an inductor coupled to a gate of a FET. An output control circuit is coupled to a timing control circuit and a bridged inductor driver, which is coupled to the inductor. A sense circuit is coupled to the gate and to the timing control circuit, which receives a control signal, generates output control signals in accordance with a first timing profile, and transmits the output control signals to the output control circuit. In accordance with the first timing profile, the output control circuit holds switches or controllable current sources of the bridged inductor driver in an ON state for a first period and holds the switches or controllable current sources in an OFF state for a second period. Gate voltages are sampled during the second period and after the first period. The timing control circuit generates a second timing profile using the sampled voltages.

The converter includes: an input direct current (DC) power supply, a main power transistor, an auxiliary power transistor, a first capacitor, a transformer, and a controller. The first capacitor is connected in series to the transformer to form a series circuit. The series circuit is connected in parallel to the auxiliary power transistor. A source of the main power transistor is connected to a drain of the auxiliary power transistor. A source of the auxiliary power transistor is connected to another electrode of the input DC power supply. An input negative electrode of the input DC power supply is grounded. The controller is configured to: monitor a value of a current on the transformer to obtain a quantity of times that the value of the current on the transformer reaches a specified current threshold.

An aspect of the disclosure relates to a radio frequency (RF) power amplifier, including a set of transistors, and a transformer including a set of primary windings and a secondary winding, wherein the set of primary windings are coupled in series with the set of transistors between a first voltage rail and a second voltage rail, wherein the set of transistors includes respective control terminals configured to receive an input RF signal, and wherein an output RF signal is produced across a load coupled in parallel with the secondary winding. In another implementation, the primary windings are primary winding portions or turns.

A switching controller generates control pulses for specifying on/off states of a first transistor and a second transistor. One end of a capacitor is coupled to a switching node. A constant voltage is applied to the other end of the capacitor via a rectifier element. A dead time controller controls a delay time between adjacent edges of the first control pulse and the second control pulse according to a sensing voltage across both ends of the capacitor.

A flyback converter and forward converter is described that include an input coil, a primary switch connected in series with the input coil, and an output coil magnetically coupled to the input coil. The input coil has an input side connected to an input of the circuit and a switch side connected to the primary switch. The converter further includes an input side clamp circuit, the input side clamp circuit including an energy store and a switch arrangement controlled such that the leakage inductance energy stored, in use, in the energy store, can be discharged to the input side of the input coil.

A zero-voltage switching (ZVS) buck-boost converter to reduce or even minimize switching power loss and improve EMI performance is described herein. The buck-boost converter may include an auxiliary path to generate an auxiliary current to charge and discharge respective nodes in the converter during select switching times. The converter may operate in buck-boost mode, buck mode, or boost mode. Moreover, the auxiliary path may include components, such as a pair of power switches and an inductor, arranged in a symmetrical fashion so that the converter may achieve ZVS in bidirectional operation as well.

The power supply apparatus alternately repeats a control between a first control of varying a frequency of switching operation within a predetermined range and for a predetermined cycle according to a frequency determined based on a feedback voltage, and a second control of varying the frequency within a range narrower than the predetermined range or a third control of controlling the frequency to be a constant frequency.