Abstract: A power converter includes an input and an output. A regulation circuit is coupled between the power converter input and the power converter output. The regulation circuit is coupled to receive a feedback signal representative of the power converter output. The feedback signal has a first feedback state that represents a level at the power converter output that is above a threshold level and a second feedback state that represents a level at the power converter output that is below the threshold level. An oscillator is included in the regulation circuit that provides an oscillation signal that cycles between two states. The regulation circuit is coupled to be responsive to the oscillation signal and to a change between the first and second feedback states to enable or disable a flow of energy from the power converter input to the power converter output.

Abstract: A power converter control method and apparatus is disclosed. An example control circuit includes a clock signal generator coupled to generate a clock signal to control switching of a power switch to be coupled to the control circuit. A feedback circuit is coupled to receive a feedback signal which is representative of an output of a power converter during a duration of a feedback portion of an off time of the power switch. The feedback circuit is coupled to respond to the feedback signal to control the clock signal generator to regulate a ratio of the duration of the feedback portion of the off time of the power switch divided by a duration of a total power switch switching cycle period.

Abstract: A power supply controller circuit is disclosed. An example power supply controller circuit includes a control circuit coupled to generate a switching waveform to be used to regulate an output of a power supply. A current input circuit is coupled to receive a current representative of an input of the power supply. The current input circuit is to generate a sense signal in response to the current representative of the input of the power supply. A first comparator is coupled to the current input circuit to receive the sense signal. The first comparator coupled to generate a first signal in response to the sense signal being above a first threshold. An enable/disable logic circuit is coupled to the first comparator. The enable/disable logic circuit is coupled to deactivate the control circuit in response to the first signal.

Abstract: A power converter includes an input and an output. A regulation circuit is coupled between the power converter input and the power converter output. The regulation circuit is coupled to receive a feedback signal representative of the power converter output. The feedback signal has a first feedback state that represents a level at the power converter output that is above a threshold level and a second feedback state that represents a level at the power converter output that is below the threshold level. An oscillator is included in the regulation circuit that provides an oscillation signal that cycles between two states. The regulation circuit is coupled to be responsive to the oscillation signal and to a change between the first and second feedback states to enable or disable a flow of energy from the power converter input to the power converter output.

Abstract: A circuit for regulating the level at a power converter output is disclosed. An example circuit includes an input for receiving a feedback signal. The feedback signal has a first feedback state that represents a level that is above a threshold level and a second feedback state that represents a level that is below the threshold level. An oscillator is included that provides an oscillation signal that cycles between two states. A switch having a first terminal, a second terminal and a control terminal are also included. The switch is operable to couple or decouple the first terminal and the second terminal in response to a control signal received at the control terminal. The control signal is responsive to the oscillation signal and to the first and second feedback states.

Abstract: A regulator for a switched mode power supply includes switching regulator logic, a counter and a switching transistor. The switching regulator logic is coupled to receive a feedback signal and to generate a switching signal in response. The feedback signal periodically cycles between a first state and a second state when the power supply operates normally. The counter is coupled to receive the feedback signal and an output of the counter indicates an auto-restart mode of the regulator in response to the feedback signal remaining in the first state for a predetermined count. The switching transistor is turned on and off in response to the switching signal when the output of the counter does not indicate the auto-restart mode and is disabled when the output of the counter indicates the auto-restart mode.

Abstract: A power switch is switched to regulate an output of a power converter. A feedback signal representative of a power converter output during a feedback portion of an off time of the power switch is received. The feedback signal is above a threshold during a fraction of the feedback portion of the off time of the power switch and the feedback signal is below the threshold during another fraction of the feedback portion of the off time of the power switch. The fractions of the feedback portion of the off time of the power switch are regulated in response to the feedback signal by controlling the switching the power switch.

Abstract: A power converter is disclosed. An example power converter includes an energy transfer element coupled between a power converter input and a power converter output. A power switch is coupled to the energy transfer element. A control circuit is coupled to receive a feedback signal representative of the power converter output during a feedback portion of an off time of the power switch. The control circuit is coupled to generate an output signal in response to the feedback signal. The output signal is coupled to be received by the power switch to control switching of the power switch to control a fraction of the feedback portion of the off time of the power switch that the feedback signal is above a threshold and another fraction of the feedback portion of the off time of the power switch that the feedback signal is below the threshold.

Abstract: A power converter control method and apparatus is disclosed. An example control circuit includes a clock signal generator coupled to generate a clock signal to control switching of a power switch to be coupled to the control circuit. A feedback circuit is coupled to receive a feedback signal which is representative of an output of a power converter during a duration of a feedback portion of an off time of the power switch. The feedback circuit is coupled to respond to the feedback signal to control the clock signal generator to regulate a ratio of the duration of the feedback portion of the off time of the power switch divided by a duration of a total power switch switching cycle period.

Abstract: A circuit for regulating the level at a power converter output is disclosed. An example circuit includes an input for receiving a feedback signal. The feedback signal has a first feedback state that represents a level that is above a threshold level and a second feedback state that represents a level that is below the threshold level. An oscillator is included that provides an oscillation signal that cycles between two states. A switch having a first terminal, a second terminal and a control terminal are also included. The switch is operable to couple or decouple the first terminal and the second terminal in response to a control signal received at the control terminal. The control signal is responsive to the oscillation signal and to the first and second feedback states.

Abstract: An example power converter includes a clock signal generator coupled to generate a clock signal to control switching of a power switch to be coupled to the control circuit. Feedback circuitry is coupled to receive a feedback signal, which is representative of an output of a power converter during a feedback portion of an off time of the power switch. The feedback circuitry is coupled to respond to the feedback signal to control the clock signal generator to regulate a duty cycle of the feedback portion of the off time of the power switch as a proportion of a total power switch switching cycle period.

Abstract: A power converter is disclosed. An example power converter includes an energy transfer element coupled between a power converter input and a power converter output. A power switch is coupled to the energy transfer element. A control circuit is coupled to receive a feedback signal representative of the power converter output during a feedback portion of an off time of the power switch. The control circuit is coupled to generate an output signal in response to the feedback signal. The output signal is coupled to be received by the power switch to control switching of the power switch to control a fraction of the feedback portion of the off time of the power switch that the feedback signal is above a threshold and another fraction of the feedback portion of the off time of the power switch that the feedback signal is below the threshold.

Abstract: A regulation circuit for use in DC to DC converter is disclosed. One such regulation circuit includes a feedback circuit to be coupled an energy transfer element output to receive a feedback signal to indicate whether the energy transfer element output is above or below a threshold level. A control circuit is included that is to be coupled to a switch that is coupled to an energy transfer element input. The control circuit is further coupled to the feedback circuit to generate a drive signal to control the switch to regulate the energy transfer element output to approximately the threshold level. The control circuit is to maintain an on-time of a current cycle of the drive signal and not allow an on-time of a next cycle of the drive signal in response to the energy transfer element output rising above the threshold level.

Abstract: A control circuit for use in a power supply is disclosed. An example control circuit according to aspects of the present invention includes a signal generator coupled to generate an output signal to control switching of a power switch to be coupled to the control circuit. A feedback circuit is coupled to receive a feedback signal, which is representative of an output of the power supply during a feedback portion of an off time of the power switch. The signal generator generates the output signal in response to the feedback circuit to control a fraction of the feedback portion of the off time of the power switch that the feedback signal is above a threshold and another fraction of the feedback portion of the off time of the power switch that the feedback signal is below the threshold.

Abstract: A power supply controller circuit is disclosed. An example power supply controller circuit includes a control circuit coupled to generate a switching waveform to be used to regulate an output of a power supply. A current input circuit is coupled to receive a current representative of an input of the power supply. The current input circuit is to generate a sense signal in response to the current representative of the input of the power supply. A first comparator is coupled to the current input circuit to receive the sense signal. The first comparator coupled to generate a first signal in response to the sense signal being above a first threshold. An enable/disable logic circuit is coupled to the first comparator. The enable/disable logic circuit is coupled to deactivate the control circuit in response to the first signal.

Abstract: A regulator for a switched mode power supply includes switching regulator logic, a counter and a logic gate. The switching regulator logic is coupled to receive a feedback signal and to generate a switching signal in response. The feedback signal periodically cycles between a first state and a second state when the power supply operates normally. The counter is coupled to receive the feedback signal and an output of the counter indicates an auto-restart mode of the regulator in response to the feedback signal remaining in the first state for a predetermined count. An output of the logic gate enables the power switch to turn on and off in response to the switching signal when the output of the counter does not indicate the auto-restart mode and the output of the logic gate disables the power switch in response to the output of the counter indicating the auto-restart mode.

Abstract: A method for controlling a power supply is disclosed. An example method includes deactivating the power supply in response to a first current through a first terminal of a power supply controller falling below a first threshold value. The power supply is activated in response to the first current through the first terminal rising above a second threshold value. Deactivating the power comprises causing a power switch coupled to a primary winding of the power supply not to receive a switching waveform for more than one cycle until the power supply is activated.

Abstract: A power converter controller circuit is disclosed. In one aspect, a power converter controller circuit includes a control circuit to generate a switching signal to be coupled to a power switch to control power delivered to an output of a power converter. A timing circuit is to be coupled to the power switch and coupled to receive a feedback signal and the switching signal. The timing circuit is to disable the power switch from receiving the switching signal in response to the feedback signal after detection of a fault condition. The feedback signal repeatedly transitions between first and second states in response to the output when the power supply operates normally. The feedback signal maintains its state when the power supply is in the fault condition. The feedback signal transitions between the first and second states independently from the switching signal.

Abstract: A method for controlling a power supply is disclosed. An example method includes deactivating the power supply in response to a first current through a first terminal of a power supply controller falling below a first threshold value. The power supply is activated in response to the first current through the first terminal rising above a second threshold value. Deactivating the power comprises causing a power switch coupled to a primary winding of the power supply not to receive a switching waveform for more than one cycle until the power supply is activated.

Abstract: A power supply controller circuit in one embodiment comprises a power switch, a multifunction circuit, and a control circuit. The power switch comprises a source and a drain respectively coupled to first and second terminals of the power supply controller circuit. The multifunction circuit comprises a first input that is coupled to a third terminal of the controller circuit, wherein the third terminal is to receive a first current control signal, and wherein the multifunction circuit is to generate a second current control signal in response to the first current control signal. The control circuit generates a switching waveform to drive a control input of the power switch in response to: an oscillating signal, a signal that is representative of current flowing through the power switch, and the second current control signal.