Abstract: A circuit for use in an LLC converter comprises a first primary side switch, a first secondary side switch assembly, and a controller. The controller is configured to measure, on the primary side of the LLC converter, a first voltage and determine, based on the first voltage, a delay due to the first voltage. The controller is also configured to apply a first gate voltage to the first primary side switch to transition the first primary side switch from an off state to an on state and apply a second gate voltage to the first secondary side switch assembly to transition the first secondary side switch assembly from an off state to an on state. The application of the first gate voltage and the application of the second gate voltage are separated by a synchronous rectifier delay based at least on the delay due to the first voltage.

Abstract: A transformer includes a magnetic structure and a set of coils. The magnetic structure includes a top member, a bottom member, and a plurality of legs extending between the top member and the bottom member. The plurality of legs include two outer legs. The set of coils is wound about the two outer legs of the magnetic structure and electrically coupled in series. In other examples, the magnetic structure includes a middle member positioned between the top member and the bottom and extending between the two outer legs. In such examples, a second set of coils is wound about the two outer legs of the magnetic structure and electrically coupled in series. Other example transformers and power converters such as multiphase interleaved power converters having transformers are also disclosed.

Abstract: A circuit for use in an LLC converter comprises a first primary side switch, a first secondary side switch assembly, and a controller. The controller is configured to measure, on the primary side of the LLC converter, a first voltage and determine, based on the first voltage, a delay due to the first voltage. The controller is also configured to apply a first gate voltage to the first primary side switch to transition the first primary side switch from an off state to an on state and apply a second gate voltage to the first secondary side switch assembly to transition the first secondary side switch assembly from an off state to an on state. The application of the first gate voltage and the application of the second gate voltage are separated by a synchronous rectifier delay based at least on the delay due to the first voltage.

Abstract: A circuit for use in an LLC converter comprises a first primary side switch, a first secondary side switch assembly, a controller, and a resonant network. The controller is configured to measure, on the LLC primary side, a first voltage and determine a delay due to the first voltage. The controller is also configured to apply a first gate voltage to the first primary side switch to transition the first primary side switch from an off state to an on state and apply a second gate voltage to the first secondary side switch assembly to transition the first secondary side switch assembly from an off state to an on state. The application of the first and second gate voltages are separated by a synchronous rectifier delay based on the delay due to the first voltage, the first voltage comprising a voltage across the resonant capacitor.

Abstract: A circuit for use in an LLC converter comprises a first primary side switch, a first secondary side switch assembly, and a controller. The controller is configured to measure, on the primary side of the LLC converter, a first voltage and determine, based on the first voltage, a delay due to the first voltage. The controller is also configured to apply a first gate voltage to the first primary side switch to transition the first primary side switch from an off state to an on state and apply a second gate voltage to the first secondary side switch assembly to transition the first secondary side switch assembly from an off state to an on state. The application of the first gate voltage and the application of the second gate voltage are separated by a synchronous rectifier delay based at least on the delay due to the first voltage.

Abstract: A circuit for use in an LLC converter comprises a first primary side switch, a first secondary side switch assembly, a controller, and a resonant network. The controller is configured to measure, on the LLC primary side, a first voltage and determine a delay due to the first voltage. The controller is also configured to apply a first gate voltage to the first primary side switch to transition the first primary side switch from an off state to an on state and apply a second gate voltage to the first secondary side switch assembly to transition the first secondary side switch assembly from an off state to an on state. The application of the first and second gate voltages are separated by a synchronous rectifier delay based on the delay due to the first voltage, the first voltage comprising a voltage across the resonant capacitor.

Abstract: A circuit for use in an LLC converter comprises a first primary side switch, a first secondary side switch assembly, and a controller. The controller is configured to measure, on the primary side of the LLC converter, a first voltage and determine, based on the first voltage, a delay due to the first voltage. The controller is also configured to apply a first gate voltage to the first primary side switch to transition the first primary side switch from an off state to an on state and apply a second gate voltage to the first secondary side switch assembly to transition the first secondary side switch assembly from an off state to an on state. The application of the first gate voltage and the application of the second gate voltage are separated by a synchronous rectifier delay based at least on the delay due to the first voltage.

Abstract: A switched mode power supply includes a multilevel buck power converter and a control circuit. The power converter includes a first buck circuit and a second buck circuit each having a power switch, a rectifier, and an inductor. The power supply may further include a resonant power converter coupled to the multilevel buck power converter. In some examples, the control circuit is configured to generate control signals for the first buck circuit's power switch and the second buck circuit's power switch to control the power converter, and adjust a switching frequency of the control signals to control the amount of reverse current flowing in the first buck circuit and the second buck circuit to achieve zero voltage switching of the first buck circuit's power switch and the second buck circuit's power switch. Other example multilevel buck power converters and power supplies are also disclosed.

Abstract: A switched mode power supply includes a multilevel buck power converter and a control circuit. The power converter includes a first buck circuit and a second buck circuit each having a power switch, a rectifier, and an inductor. The power supply may further include a resonant power converter coupled to the multilevel buck power converter. In some examples, the control circuit is configured to generate control signals for the first buck circuit's power switch and the second buck circuit's power switch to control the power converter, and adjust a switching frequency of the control signals to control the amount of reverse current flowing in the first buck circuit and the second buck circuit to achieve zero voltage switching of the first buck circuit's power switch and the second buck circuit's power switch. Other example multilevel buck power converters and power supplies are also disclosed.

Abstract: A transformer includes a magnetic structure and a set of coils. The magnetic structure includes a top member, a bottom member, and a plurality of legs extending between the top member and the bottom member. The plurality of legs include two outer legs. The set of coils is wound about the two outer legs of the magnetic structure and electrically coupled in series. In other examples, the magnetic structure includes a middle member positioned between the top member and the bottom and extending between the two outer legs. In such examples, a second set of coils is wound about the two outer legs of the magnetic structure and electrically coupled in series. Other example transformers and power converters such as multiphase interleaved power converters having transformers are also disclosed.

Abstract: According to some aspects of the present disclosure, isolated power supplies and corresponding control methods are disclosed. Example isolated power supplies include a transformer, at least one power switch coupled to the transformer, a controller, an output terminal, and a feedback circuit coupled to the output terminal to sense the output voltage and compare the sensed output voltage to a voltage reference. The power supplies include a fault detection circuit to sense the output voltage, compare the sensed output voltage to a fault reference, and modify a feedback signal when the sensed output voltage exceeds the fault reference. The power supplies also include a single isolation device coupled between the feedback circuit and the controller. The controller is operable to control the power switch based on the feedback signal and to detect a fault condition when a slew rate of the feedback signal exceeds a fault threshold slew rate value.

Abstract: A control circuit includes a first integrator circuit corresponding to a first mode and a second integrator circuit corresponding to a second mode. The control circuit is configured to transition control of the power converter between the first mode and the second mode such that one of the first mode and the second mode is a controlling mode for a period of time and the other one of the first mode and the second mode is a non-controlling mode for the period of time, and set an output of the first integrator circuit or the second integrator circuit corresponding to the non-controlling mode to equal an output of the first integrator circuit or the second integrator circuit corresponding to the controlling mode. Other example control circuits, power converters including a control circuit, and methods for controlling a power converter are also disclosed.

Abstract: According to some aspects of the present disclosure, isolated power supplies and corresponding control methods are disclosed. Example isolated power supplies include a transformer, at least one power switch coupled to the transformer, a controller, an output terminal, and a feedback circuit coupled to the output terminal to sense the output voltage and compare the sensed output voltage to a voltage reference. The power supplies include a fault detection circuit to sense the output voltage, compare the sensed output voltage to a fault reference, and modify a feedback signal when the sensed output voltage exceeds the fault reference. The power supplies also include a single isolation device coupled between the feedback circuit and the controller. The controller is operable to control the power switch based on the feedback signal and to detect a fault condition when a slew rate of the feedback signal exceeds a fault threshold slew rate value.

Abstract: A control circuit includes a first integrator circuit corresponding to a first mode and a second integrator circuit corresponding to a second mode. The control circuit is configured to transition control of the power converter between the first mode and the second mode such that one of the first mode and the second mode is a controlling mode for a period of time and the other one of the first mode and the second mode is a non-controlling mode for the period of time, and set an output of the first integrator circuit or the second integrator circuit corresponding to the non-controlling mode to equal an output of the first integrator circuit or the second integrator circuit corresponding to the controlling mode. Other example control circuits, power converters including a control circuit, and methods for controlling a power converter are also disclosed.

Abstract: A method of optimizing a gain adjustment value Kadj for a digital controller in an isolated switched mode power supply. The power supply includes an opto-coupler having a current transfer ratio (CTRX) within a range defined by a minimum current transfer ratio (CTRMIN) and a maximum current transfer ratio (CTRMAX). The method includes determining the CTRX of the opto-coupler, determining an optimal gain adjustment value KadjX based on the determined CTRX of the opto-coupler, and storing the optimal gain adjustment value KadjX in the digital controller. The method can be performed by the digital controller or by a programming device external to the power supply.

Abstract: A method of optimizing a gain adjustment value Kadj for a digital controller in an isolated switched mode power supply. The power supply includes an opto-coupler having a current transfer ratio (CTRX) within a range defined by a minimum current transfer ratio (CTRMIN) and a maximum current transfer ratio (CTRMAX). The method includes determining the CTRX of the opto-coupler, determining an optimal gain adjustment value KadjX based on the determined CTRX of the opto-coupler, and storing the optimal gain adjustment value KadjX in the digital controller. The method can be performed by the digital controller or by a programming device external to the power supply.