Abstract: A switched-mode power controller includes a primary side controller circuit configured in a startup mode of operation to generate a fixed switching frequency pulse width modulation (PWM) signal with incrementing duty-ratio value. The PWM signal drives a main-switch that charges an inductive device with stored energy and discharges the stored energy into a capacitor on a secondary side to generate a power controller output voltage. Based on a comparison of the power controller output voltage with a reference voltage, the primary side controller circuit is configured to stop the incrementing of the duty-ratio of the PWM signal and begin a quasi-resonant mode of operation during which the primary side controller circuit reduces a number of valleys detected in one or more off-times of the main-switch in one or more respective main-switch switching periods.

Abstract: A flyback converter includes a primary-side circuit to receive an input voltage, a secondary-side circuit to generate an output voltage, a transformer coupling the primary-side circuit to the secondary-side circuit, a main switch coupled to a primary winding of the transformer, and a converter controller having a primary-side controller in signal communication with the main switch to control an on time and an off time of the main switch and to detect one or more valleys of a resonant waveform developed at the main switch during the off time of the main switch. The primary-side controller is configured to operate in a valley reduction mode of operation upon determining that the output voltage is less than a reference voltage minus a predetermined threshold value. The valley reduction mode of operation includes decrementing, for each switching cycle of the main switch, a number of valleys occurring during that switching cycle.

Abstract: An active clamp circuit includes an active clamp switch having a drain node and a source node, an active clamp capacitor coupled in a series combination with the active clamp switch, a delay circuit, and an active clamp controller circuit coupled to the active clamp switch and to the delay circuit. The active clamp controller circuit is configured to i) receive an active clamp switch voltage based on a voltage developed across the drain node and the source node of the active clamp switch, ii) enable the active clamp switch based on a voltage amplitude of the active clamp switch voltage, and iii) disable the active clamp switch based on a delay signal generated by the delay circuit.

Abstract: A power converter controller includes a fractional valley controller configured to determine a target number of valleys of a resonant waveform at a drain node of a main switch, the target number of valleys corresponding to a desired off-time of the main switch, the fractional valley controller modulating an off-time of the main switch between two or more modulated off-times. The target number of valleys corresponds to a non-integer number of valleys of the resonant waveform at the drain node of the main switch. Each of the modulated off-times of the main switch corresponds to an integer number of valleys, and the two or more modulated off-times of the main switch has an average value that corresponds to the desired off-time.

Abstract: The combined voltage regulator and snubber circuit generally has a voltage regulator device in parallel with the energy storage element of the snubber circuit operatively connectable in series with a leakage inductance current path; the leakage inductance being part of a magnetic component utilized in a switch-mode power supply having an input voltage source, controllable semiconductor switches, freewheeling semiconductor switches, feedback controller, reactive energy storage components and a load; the voltage regulator generally providing constant or variable voltage to the gate driver of the controllable semiconductor and/or feedback controller; the snubber circuit generally recycling leakage inductance energy to the input capacitor of a neighboring cell in a multi-cell stacked converter.

Abstract: A switch-mode power supply controller controls a circuit that includes a flyback-based, switch-mode power supply in the context of an input voltage source, a USB Type-C PD controller and an output load. The switch-mode power supply controller may be configured to estimate input voltage based on a measured magnetizing inductance discharge time. Furthermore, the switch-mode power supply controller may be configured to estimate output voltage based on the measured magnetizing inductance discharge time and the estimated input voltage. Still further, the estimated voltages may be used by the switch-mode power supply controller to limit certain currents and optimize power efficiency. Even further, the estimated and measured value may be employed by the switch-mode power supply controller to estimate and indicate brownout conditions.

Abstract: A power converter includes an input side to receive an input voltage, and an output side to provide an output voltage, a main switch, a controller, a transformer having a primary winding that couples the main switch to the input side, an active clamp switch coupled to the input side by an active clamp capacitor, and an active clamp controller circuit. The active clamp controller circuit includes a sampling circuit to generate a sampled main switch voltage, a delay circuit to generate a delayed sampled main switch voltage, a voltage comparison circuit, and an active clamp switch control circuit configured to i) enable the active clamp switch based on a first comparison between the sampled main switch voltage and the delayed sampled main switch voltage, and ii) disable the active clamp switch based on a second comparison between the sampled main switch voltage and the delayed sampled main switch voltage.

Abstract: The anti-windup circuit generally has a voltage clamping device in series with a current limiting device operatively connectable to the output current path of a feedback compensator; the feedback compensator being part of a switch-mode power supply (SMPS) having an input voltage source and a load and generating constrained control values required to generate control on-off actions for tight power regulation. The inclusion of the disclosed anti-windup circuit in an SMPS may lead to hardware based overvoltage protection, reduced overall size and faster response to load changes.

Abstract: A switched-mode power controller includes a primary side controller circuit configured in a startup mode of operation to generate a fixed switching frequency pulse width modulation (PWM) signal with incrementing duty-ratio value. The PWM signal drives a main-switch that charges an inductive device with stored energy and discharges the stored energy into a capacitor on a secondary side to generate a power controller output voltage. Based on a comparison of the power controller output voltage with a reference voltage, the primary side controller circuit is configured to stop the incrementing of the duty-ratio of the PWM signal and begin a quasi-resonant mode of operation during which the primary side controller circuit reduces a number of valleys detected in one or more off-times of the main-switch in one or more respective main-switch switching periods.

Abstract: A power converter controller includes a fractional valley controller configured to determine a target number of valleys of a resonant waveform at a drain node of a main switch, the target number of valleys corresponding to a desired off-time of the main switch, the fractional valley controller modulating an off-time of the main switch between two or more modulated off-times. The target number of valleys corresponds to a non-integer number of valleys of the resonant waveform at the drain node of the main switch. Each of the modulated off-times of the main switch corresponds to an integer number of valleys, and the two or more modulated off-times of the main switch has an average value that corresponds to the desired off-time.

Abstract: The flyback converter generally has a capacitive divider operatively connectable to a voltage source for receiving an input voltage, the capacitive divider having a plurality of capacitive devices connected in series from one another; a transformer having a plurality of primary windings inductively coupled to at least one secondary winding, each one of the primary windings of the transformer being connected in parallel to a corresponding one of the capacitive devices of the capacitive divider via a switching device, each of the at least one secondary winding being connected to a forwardly biased and capacitive circuit connectable to an output load; and a controller connected to each one of the switching devices for operating the flyback converter to power the output load with the voltage source.

Abstract: An active clamp circuit includes an active clamp capacitor coupled in series with an active clamp switch and an active clamp controller circuit to receive an active clamp switch current that passes through the active clamp switch and to control the active clamp switch based on the received active clamp switch current. The active clamp controller circuit is configured to enable the active clamp switch based on a first amplitude comparison, the first amplitude comparison being based on the active clamp switch current. The active clamp controller circuit is configured to disable the active clamp switch based on a second amplitude comparison and a third amplitude comparison, the second amplitude comparison and the third amplitude comparison being based on the active clamp switch current.

Abstract: A power converter includes an input side to receive an input voltage, and an output side to provide an output voltage, a main switch, a controller, a transformer having a primary winding that couples the main switch to the input side, an active clamp switch coupled to the input side by an active clamp capacitor, and an active clamp controller circuit. The active clamp controller circuit includes a sampling circuit to generate a sampled main switch voltage, a delay circuit to generate a delayed sampled main switch voltage, a voltage comparison circuit, and an active clamp switch control circuit configured to i) enable the active clamp switch based on a first comparison between the sampled main switch voltage and the delayed sampled main switch voltage, and ii) disable the active clamp switch based on a second comparison between the sampled main switch voltage and the delayed sampled main switch voltage.

Abstract: The anti-windup circuit generally has a voltage clamping device in series with a current limiting device operatively connectable to the output current path of a feedback compensator; the feedback compensator being part of a switch-mode power supply (SMPS) having an input voltage source and a load and generating constrained control values required to generate control on-off actions for tight power regulation. The inclusion of the disclosed anti-windup circuit in an SMPS may lead to hardware based overvoltage protection, reduced overall size and faster response to load changes.

Abstract: The combined voltage regulator and snubber circuit generally has a voltage regulator device in parallel with the energy storage element of the snubber circuit operatively connectable in series with a leakage inductance current path; the leakage inductance being part of a magnetic component utilized in a switch-mode power supply having an input voltage source, controllable semiconductor switches, freewheeling semiconductor switches, feedback controller, reactive energy storage components and a load; the voltage regulator generally providing constant or variable voltage to the gate driver of the controllable semiconductor and/or feedback controller; the snubber circuit generally recycling leakage inductance energy to the input capacitor of a neighbouring cell in a multi-cell stacked converter.

Abstract: The combined voltage regulator and snubber circuit generally has a voltage regulator device in parallel with the energy storage element of the snubber circuit operatively connectable in series with a leakage inductance current path; the leakage inductance being part of a magnetic component utilized in a switch-mode power supply having an input voltage source, controllable semiconductor switches, freewheeling semiconductor switches, feedback controller, reactive energy storage components and a load; the voltage regulator generally providing constant or variable voltage to the gate driver of the controllable semiconductor and/or feedback controller; the snubber circuit generally recycling leakage inductance energy to the input capacitor of a neighboring cell in a multi-cell stacked converter.

Abstract: A switch-mode power supply controller controls a circuit that includes a flyback-based, switch-mode power supply in the context of an input voltage source, a USB Type-C PD controller and an output load. The switch-mode power supply controller may be configured to estimate input voltage based on a measured magnetizing inductance discharge time. Furthermore, the switch-mode power supply controller may be configured to estimate output voltage based on the measured magnetizing inductance discharge time and the estimated input voltage. Still further, the estimated voltages may be used by the switch-mode power supply controller to limit certain currents and optimize power efficiency. Even further, the estimated and measured value may be employed by the switch-mode power supply controller to estimate and indicate brownout conditions.

Abstract: A combined voltage regulator and snubber circuit generally has a voltage regulator device in parallel with the energy storage element of the snubber circuit operatively connectable in series with a leakage inductance current path; the leakage inductance being part of a magnetic component utilized in a switch-mode power supply having an input voltage source, controllable semiconductor switches, freewheeling semiconductor switches, feedback controller, reactive energy storage components and a load; the voltage regulator generally providing constant or variable voltage to the gate driver of the controllable semiconductor and/or feedback controller.

Abstract: The flyback converter generally has a capacitive divider operatively connectable to a voltage source for receiving an input voltage, the capacitive divider having a plurality of capacitive devices connected in series from one another; a transformer having a plurality of primary windings inductively coupled to at least one secondary winding, each one of the primary windings of the transformer being connected in parallel to a corresponding one of the capacitive devices of the capacitive divider via a switching device, each of the at least one secondary winding being connected to a forwardly biased and capacitive circuit connectable to an output load; and a controller connected to each one of the switching devices for operating the flyback converter to power the output load with the voltage source.

Abstract: A combined voltage regulator and snubber circuit generally has a voltage regulator device in parallel with the energy storage element of the snubber circuit operatively connectable in series with a leakage inductance current path; the leakage inductance being part of a magnetic component utilized in a switch-mode power supply having an input voltage source, controllable semiconductor switches, freewheeling semiconductor switches, feedback controller, reactive energy storage components and a load; the voltage regulator generally providing constant or variable voltage to the gate driver of the controllable semiconductor and/or feedback controller.