Abstract: Systems and methods that automatically detect state of switches in power converters are disclosed. In one aspect, a power switch includes a first switch coupled between a power input node and a first terminal of a load, a second switch coupled between the power input node and a second terminal of the load, first and second current sense devices arranged to transmit first and second signals including at least one of a magnitude and polarity of first and second currents through the first and second switches, respectively, a first driver circuit arranged to transmit first control signals to the first switch based at least in part on a voltage at the power input node and the first signal, and a second driver circuit arranged to transmit second control signals to the second switch based at least in part on the voltage at the power input node and the second signal.

Abstract: A flyback DC-DC converter. The converter having a transformer with a primary and a secondary windings, first and second switches, a capacitor coupled between the second switch and the primary winding, where the second switch is arranged to operate such that a sum of a first and second time periods equals a sum of third and fourth time periods, where the first time period is a delay time period from a time that the first switch is turned off to a time that the second switch is turned on, the second time period is a time period that the second switch is on, the third time period is a resonance time period of a resonator formed by a leakage inductance of the transformer and a capacitance of the capacitor, and the fourth time period is a time period for discharge of the leakage inductance of the transformer into the capacitor.

Abstract: Systems and methods that automatically detect state of switches in power converters are disclosed. In one aspect, a power switch includes a first switch coupled between a power input node and a first terminal of a load, a second switch coupled between the power input node and a second terminal of the load, first and second current sense devices arranged to transmit first and second signals including at least one of a magnitude and polarity of first and second currents through the first and second switches, respectively, a first driver circuit arranged to transmit first control signals to the first switch based at least in part on a voltage at the power input node and the first signal, and a second driver circuit arranged to transmit second control signals to the second switch based at least in part on the voltage at the power input node and the second signal.

Abstract: A method of operating a circuit is disclosed. The method includes providing an interleaved power factor correction (PFC) converter circuit; determining a switching frequency of the interleaved PFC converter circuit; setting a phase shift of the interleaved PFC converter circuit at a first phase shift when the switching frequency of the interleaved PFC converter circuit is below or at a first switching frequency; setting the phase shift of the interleaved PFC converter circuit at a second phase shift when the switching frequency of the interleaved PFC converter circuit is greater than the first switching frequency but less than a second switching frequency; and setting the phase shift of the interleaved PFC converter circuit at the first phase shift when the switching frequency of interleaved the PFC converter circuit is greater than the second switching frequency.

Abstract: Systems and methods that automatically detect state of switches in power converters are disclosed. In one aspect, a power switch includes a first switch coupled between a power input node and a first terminal of a load, a second switch coupled between the power input node and a second terminal of the load, first and second current sense devices arranged to transmit first and second signals including at least one of a magnitude and polarity of first and second currents through the first and second switches, respectively, a first driver circuit arranged to transmit first control signals to the first switch based at least in part on a voltage at the power input node and the first signal, and a second driver circuit arranged to transmit second control signals to the second switch based at least in part on the voltage at the power input node and the second signal.

Abstract: A synchronous rectifier circuit is self-powered by a portion of a secondary winding. A transformer has a primary winding arranged to receive power from a power source, a secondary winding arranged to transfer power to a load, and a tapped output arranged to transfer power to a controller circuit, wherein the tapped output is formed from a portion of the secondary windings. The controller circuit uses power from the tapped output to drive a synchronous switch disposed between the secondary winding and the load. The synchronous switch rectifies the power received from the secondary winding such that DC power can be supplied to a load.

Abstract: A circuit. The circuit includes a transformer having a primary winding extending between a first terminal and a second terminal, and a secondary winding extending between a third terminal and a first output terminal, and an auxiliary winding extending between a fourth terminal and the third terminal; a first switch having a first gate terminal, a first source terminal and a first drain terminal, the first drain terminal coupled to the second terminal and the first source terminal coupled to a power source; a second switch having a second gate terminal, a second source terminal and a second drain terminal, the second source terminal coupled to the third terminal and the second drain terminal coupled to a second output terminal, the secondary winding having a winding direction opposite to that of the primary winding and the auxiliary winding having a winding direction same as that of the primary winding.

Abstract: A circuit is disclosed. The circuit includes a transformer having a primary winding extending between a first terminal and a second terminal, and further including a secondary winding extending between a third terminal and a first output terminal; a first switch having a first gate terminal, a first source terminal and a first drain terminal, the first drain terminal coupled to the second terminal and the first source terminal coupled to a power source; a second switch having a second gate terminal, a second source terminal and a second drain terminal, the second source terminal coupled to the second terminal, and the second drain terminal coupled to the power source; and a third switch having a third gate terminal, a third source terminal and a third drain terminal, the third source terminal coupled to the third terminal and the third drain terminal coupled to a second output terminal.

Abstract: Methods of operating a circuit are disclosed. In one aspect, disclosed methods includes providing a power converter circuit having transformer with a primary winding and secondary winding, a first switch and second switch coupled to the primary winding, a third switch coupled to the secondary winding, a controller coupled to the first and second switches. Disclosed methods further includes sensing a turn-on of the third switch and in response, transmitting a turn-on signal to the controller; and turning-on the second switch, using the controller, in response to receiving the turn-on signal. In another aspect, disclosed methods further includes sensing a turn-off of the third switch and in response, transmitting a turn-off signal to the controller using an isolation module, and turning-off the second switch, using the controller, in response to receiving the turn-off signal. In yet another aspect, the second switch is turned-off, using the controller, after a delay time.

Abstract: An electronic device is disclosed. In one aspect, the electronic device includes a printed circuit board (PCB) having a first surface and a second surface opposite the first surface, where the PCB includes a thermally conductive region having a plurality of vias that extend from the first surface to the second surface; a semiconductor device attached to the second surface of the PCB and overlying the thermally conductive region; a transformer having a magnetic core; a shield arranged to partially enclose the transformer and define an opening; and an insert disposed within the opening, attached to the first surface of the PCB and overlying the thermally conductive region.

Abstract: Systems and methods for improving radiated electromagnetic interference (EMI) in switching power supplies are disclosed. In one aspect, a converter circuit includes a transformer having a primary winding and a secondary winding, the primary winding extending from a first primary terminal to a second primary terminal, a first switch having a first gate terminal, a first source terminal and a first drain terminal, wherein the first drain terminal is coupled to the first primary terminal, and the first source terminal is coupled to a power source, and a capacitor having a first capacitor terminal and second capacitor terminal, wherein the first capacitor terminal is coupled to the power source. A ferrite bead is coupled between the first primary terminal and the first drain terminal, and a capacitor network is coupled in parallel with the ferrite bead and arranged to reduce radiated electromagnetic interference of the converter circuit.

Abstract: A low power-loss supply circuit minimizes the losses in a synchronous rectifier power conversion circuit by regulating the voltage supply (Vcc) of a synchronous rectifier controller. The low power-loss supply circuit uses two regulating capacitors to regulate the value of the voltage supplied to the controller. A first regulating capacitor supplies the input voltage which powers the synchronous rectifier controller. A second regulating capacitor is used to cyclically charge the first regulating capacitor.

Abstract: Systems and methods that automatically detect state of switches in power converters are disclosed. In one aspect, a power switch includes a first switch coupled between a power input node and a first terminal of a load, a second switch coupled between the power input node and a second terminal of the load, first and second current sense devices arranged to transmit first and second signals including at least one of a magnitude and polarity of first and second currents through the first and second switches, respectively, a first driver circuit arranged to transmit first control signals to the first switch based at least in part on a voltage at the power input node and the first signal, and a second driver circuit arranged to transmit second control signals to the second switch based at least in part on the voltage at the power input node and the second signal.

Abstract: Systems and methods that automatically detect state of switches in power converters are disclosed. In one aspect, a power switch includes a first switch coupled between a power input node and a first terminal of a load, a second switch coupled between the power input node and a second terminal of the load, first and second current sense devices arranged to transmit first and second signals including at least one of a magnitude and polarity of first and second currents through the first and second switches, respectively, a first driver circuit arranged to transmit first control signals to the first switch based at least in part on a voltage at the power input node and the first signal, and a second driver circuit arranged to transmit second control signals to the second switch based at least in part on the voltage at the power input node and the second signal.

Abstract: A flyback DC-DC converter. The converter having a transformer with a primary and a secondary windings, first and second switches, a capacitor coupled between the second switch and the primary winding, where the second switch is arranged to operate such that a sum of a first and second time periods equals a sum of third and fourth time periods, where the first time period is a delay time period from a time that the first switch is turned off to a time that the second switch is turned on, the second time period is a time period that the second switch is on, the third time period is a resonance time period of a resonator formed by a leakage inductance of the transformer and a capacitance of the capacitor, and the fourth time period is a time period for discharge of the leakage inductance of the transformer into the capacitor.

Abstract: Systems and methods for reducing auxiliary transformer winding turns are disclosed. In one aspect, a circuit includes a transformer having a primary winding, a secondary winding and an auxiliary winding having a first end and a second end, a diode having a cathode and an anode, the anode coupled to the first end of the auxiliary winding, and a capacitor having a first terminal coupled to the second end of the auxiliary winding, and a second terminal coupled to the cathode.

Abstract: Systems and methods that automatically detect state of switches in power converters are disclosed. In one aspect, a power switch includes a first switch coupled between a power input node and a first terminal of a load, a second switch coupled between the power input node and a second terminal of the load, first and second current sense devices arranged to transmit first and second signals including at least one of a magnitude and polarity of first and second currents through the first and second switches, respectively, a first driver circuit arranged to transmit first control signals to the first switch based at least in part on a voltage at the power input node and the first signal, and a second driver circuit arranged to transmit second control signals to the second switch based at least in part on the voltage at the power input node and the second signal.

Abstract: Systems and methods for improving winding losses in transformers are disclosed. In one aspect, a transformer includes a first magnetic core having an interior portion and an exterior portion, a second magnetic core in contact with the interior and exterior portions, a plurality of primary and secondary windings formed around the interior portion, where the interior portion is formed from one of a first magnetic material and a second magnetic material, and the exterior portion is formed from one of the first magnetic material and the second magnetic material, where the first magnetic material has different properties than the second magnetic material. In another aspect, the first magnetic core includes a third portion that extends across and is in contact with the interior portion and the exterior portion, where the third portion is formed from one of the first magnetic material and the second magnetic material.

Abstract: Systems and methods for improving winding losses in transformers. In one aspect, a transformer includes a first magnetic core having a first portion in contact with a second magnetic core and a second portion separated from the second magnetic core by a distance d, a plurality of primary windings formed around the second portion, a first secondary winding forming a first layer having a first inner diameter, a second secondary winding forming an nth layer having a second inner diameter. The plurality of primary windings are positioned between the first layer and the nth layer, where the plurality of primary windings, and the first secondary winding and the second secondary winding are formed around the second portion, and a difference between the first inner diameter and the second inner diameter defines a distance y, and a ratio of distance y to distance d is between 0.01 to 10.

Abstract: Systems and methods that automatically detect state of switches in power converters are disclosed. In one aspect, a power switch includes a first switch coupled between a power input node and a first terminal of a load, a second switch coupled between the power input node and a second terminal of the load, first and second current sense devices arranged to transmit first and second signals including at least one of a magnitude and polarity of first and second currents through the first and second switches, respectively, a first driver circuit arranged to transmit first control signals to the first switch based at least in part on a voltage at the power input node and the first signal, and a second driver circuit arranged to transmit second control signals to the second switch based at least in part on the voltage at the power input node and the second signal.