Abstract: A first controller for a power converter, the first controller comprising a driver, supply terminal, branch switch and branch control. The driver configured to provide a drive signal to turn ON and turn OFF a power switch. The power switch includes a first switch and a second switch coupled in a cascode configuration. The supply terminal coupled to a bypass capacitor that provides operating power to the first controller, wherein the bypass capacitor has a bypass voltage. The branch switch coupled to a node between the first switch and the second switch. The branch control configured to receive a regulation signal representative of a comparison of the bypass voltage to a bypass reference and is configured to turn ON the branch switch if the bypass voltage is below the bypass reference to redirect at least a portion of a drain current of the power switch to the bypass capacitor.

Abstract: A control circuit comprising an output controller coupled to an output side of a power converter. The output controller comprises a switch control signal generator to receive a feedback signal representative of an output of the power controller and to communicate a control signal to an input controller coupled to an input side to control a turn ON of a power switch. The control signal is generated in response to the feedback signal and is communicated in response to an enable signal. The output controller comprises an extremum locator to generate the enable signal in response to a winding signal representative of an instantaneous voltage on an output terminal of an energy transfer element and the extremum locator enables the switch control signal generator such that the transition of the power switch from the OFF state to the ON state occurs substantially when the winding signal reaches an extremum.

Abstract: A first controller for a power converter, the first controller comprising a driver, supply terminal, branch switch and branch control. The driver configured to provide a drive signal to turn ON and turn OFF a power switch. The power switch includes a first switch and a second switch coupled in a cascode configuration. The supply terminal coupled to a bypass capacitor that provides operating power to the first controller, wherein the bypass capacitor has a bypass voltage. The branch switch coupled to a node between the first switch and the second switch. The branch control configured to receive a regulation signal representative of a comparison of the bypass voltage to a bypass reference and is configured to turn ON the branch switch if the bypass voltage is below the bypass reference to redirect at least a portion of a drain current of the power switch to the bypass capacitor.

Abstract: A method for providing a jitter signal for modulating a switching frequency of a power switch for a power converter. The method comprising receiving a drive signal representative of the switching frequency of the power switch, detecting the switching frequency from the drive signal, determining if the switching frequency is less than a first threshold frequency, and modulating a frequency of the jitter signal in response to determining if the switching frequency is less than the first threshold frequency.

Abstract: A controller to regulate a power converter includes a terminal that receives an enable signal including enable events representative of an output of the power converter. A drive circuit generates a drive signal to control switching of a power switch to control an energy transfer from an input to an output of the power converter. The drive circuit turns on the power switch when an enable event is received in the enable signal. A current limit threshold generator is coupled to the drive circuit to generate a threshold signal. The threshold signal increases in response to the power switch turning off and subsequently decreases. The threshold signal and a time between consecutive enable events are used to modulate the drive signal to regulate the output of the power converter.

Abstract: A switched mode power converter has an energy transfer element that delivers an output signal to a load. A power switching device coupled to the primary side of the energy transfer element regulates a transfer of energy to the load. A secondary controller is coupled to receive a feedback signal and output a pulsed signal in response thereto. A primary controller is coupled to receive the pulsed signal and output a drive signal in response thereto, the drive signal being coupled to control switching of the power switching device. A compensation circuit generates an adaptively compensated signal synchronous with the pulsed signal. The adaptively compensated signal has a parameter that is adaptively adjusted in response to a comparison of the feedback signal with a threshold reference signal. The parameter converges towards a final value that produces a desired level of the output signal.

Abstract: A method for providing a jitter signal for modulating a switching frequency of a power switch for a power converter. The method comprising receiving a drive signal representative of the switching frequency of the power switch, detecting the switching frequency from the drive signal, determining if the switching frequency is less than a first threshold frequency, and modulating a frequency of the jitter signal in response to determining if the switching frequency is less than the first threshold frequency.

Abstract: A control circuit comprising an output controller coupled to an output side of a power converter. The output controller comprises a switch control signal generator to receive a feedback signal representative of an output of the power controller and to communicate a control signal to an input controller coupled to an input side to control a turn ON of a power switch. The control signal is generated in response to the feedback signal and is communicated in response to an enable signal. The output controller comprises an extremum locator to generate the enable signal in response to a winding signal representative of an instantaneous voltage on an output terminal of an energy transfer element and the extremum locator enables the switch control signal generator such that the transition of the power switch from the OFF state to the ON state occurs substantially when the winding signal reaches an extremum.

Abstract: A controller for use in a power converter including a jitter generator circuit coupled to receive a drive signal from a switch controller and generate a jitter signal. The jitter signal is a modulated jitter signal when the drive signal is below a first threshold frequency. The switch controller is coupled to a power switch coupled to an energy transfer element. The switch controller is coupled to receive a current sense signal representative of a current through the power switch. The switch controller is coupled to generate the drive signal to control switching of the power switch in response to the current sense signal and the jitter signal to control a transfer of energy from an input of the power converter to an output of the power converter.

Abstract: A method of providing an input switching request signal to an input side switch includes determining a switching request window indicative of relaxation ringing during a first switching cycle. It is determined that the input side switch is operating in a discontinuous conduction mode (DCM) mode of operation during a second switching cycle. It is determined that the switching request window is open during the second switching cycle. The input switching request signal is enabled in response to determining the switching request window is open.

Abstract: A controller to regulate a power converter includes a terminal that receives an enable signal including enable events representative of an output of the power converter. A drive circuit generates a drive signal to control switching of a power switch to control an energy transfer from an input to an output of the power converter. The drive circuit turns on the power switch when an enable event is received in the enable signal. A current limit threshold generator is coupled to the drive circuit to generate a threshold signal. The threshold signal increases in response to the power switch turning off and subsequently decreases. The threshold signal and a time between consecutive enable events are used to modulate the drive signal to regulate the output of the power converter.

Abstract: A controller includes a current limit generator that generates a current limit threshold. A switch controller receives the current limit threshold, an enable signal, and a current sense signal representative of a current through a power switch. The switch controller generates a drive signal to control switching of the power switch to control the transfer of energy from an input of the power converter to an output of the power converter in response to the enable signal and the current sense signal. The switch controller outputs the drive signal to turn on the power switch in response to the enable signal and turns off the power switch when the current sense signal reaches the current limit threshold. A jitter generator generates a jitter signal for jittering a switching period of the drive signal. The current limit threshold is modulated by the jitter signal.

Abstract: A controller to regulate a power converter includes a terminal coupled to receive an enable signal including enable events representative of an output of the power converter. A drive circuit is coupled to generate a drive signal to control switching of a power switch to control a transfer of energy from an input of the power converter to the output of the power converter. The drive circuit is coupled to turn on the power switch when an enable event is received in the enable signal. A current limit threshold generator is coupled to the drive circuit to generate a current limit threshold signal. The current limit threshold signal varies each switching cycle of the power switch. A time between consecutive enable events in the enable signal is the switching cycle of the power switch.

Abstract: A controller for use in a power converter including a jitter generator circuit coupled to receive a drive signal from a switch controller and generate a jitter signal. The jitter signal is a modulated jitter signal when the drive signal is below a first threshold frequency. The switch controller is coupled to a power switch coupled to an energy transfer element. The switch controller is coupled to receive a current sense signal representative of a current through the power switch. The switch controller is coupled to generate the drive signal to control switching of the power switch in response to the current sense signal and the jitter signal to control a transfer of energy from an input of the power converter to an output of the power converter.

Abstract: A controller for use in a power converter including a jitter generator circuit coupled to receive a drive signal from a switch controller and generate a jitter signal. The jitter signal is a modulated jitter signal when the drive signal is below a first threshold frequency. The switch controller is coupled to a power switch coupled to an energy transfer element. The switch controller is coupled to receive a current sense signal representative of a current through the power switch. The switch controller is coupled to generate the drive signal to control switching of the power switch in response to the current sense signal and the jitter signal to control a transfer of energy from an input of the power converter to an output of the power converter.

Abstract: A controller includes a current limit generator that generates a current limit threshold. A switch controller receives the current limit threshold, an enable signal, and a current sense signal representative of a current through a power switch. The switch controller generates a drive signal to control switching of the power switch to control the transfer of energy from an input of the power converter to an output of the power converter in response to the enable signal and the current sense signal. The switch controller outputs the drive signal to turn on the power switch in response to the enable signal and turns off the power switch when the current sense signal reaches the current limit threshold. A jitter generator generates a jitter signal for jittering a switching period of the drive signal. The current limit threshold is modulated by the jitter signal.

Abstract: A switched mode power converter has an energy transfer element that delivers an output signal to a load. A power switching device coupled to the primary side of the energy transfer element regulates a transfer of energy to the load. A secondary controller is coupled to receive a feedback signal and output a pulsed signal in response thereto. A primary controller is coupled to receive the pulsed signal and output a drive signal in response thereto, the drive signal being coupled to control switching of the power switching device. A compensation circuit generates an adaptively compensated signal synchronous with the pulsed signal. The adaptively compensated signal has a parameter that is adaptively adjusted in response to a comparison of the feedback signal with a threshold reference signal. The parameter converges towards a final value that produces a desired level of the output signal.

Abstract: A controller includes a switch controller, a current limit generator, a jitter modulator, and an arithmetic operator circuit. The switch controller is coupled to generate a drive signal to control switching of a power switch in response to a current sense signal and a modulated current limit signal to control a transfer of energy from an input of a power converter to an output of the power converter. The current limit generator is coupled to generate a current limit signal. The jitter modulator is coupled to generate a jitter signal for jittering a switching period of the drive signal without an oscillator. The arithmetic operator circuit is coupled to receive the current limit signal and the jitter signal and is coupled to generate a modulated current limit signal in response to the current limit signal and the jitter signal.

Abstract: A switched mode power converter has an energy transfer element that delivers an output signal to a load. A power switching device coupled to the primary side of the energy transfer element regulates a transfer of energy to the load. A secondary controller is coupled to receive a feedback signal and output a pulsed signal in response thereto. A primary controller is coupled to receive the pulsed signal and output a drive signal in response thereto, the drive signal being coupled to control switching of the power switching device. A compensation circuit generates an adaptively compensated signal synchronous with the pulsed signal. The adaptively compensated signal has a parameter that is adaptively adjusted in response to a comparison of the feedback signal with a threshold reference signal. The parameter converges towards a final value that produces a desired level of the output signal.

Abstract: A controller includes a switch controller, a current limit generator, a jitter modulator, and an arithmetic operator circuit. The switch controller is coupled to generate a drive signal to control switching of a power switch in response to a current sense signal and a modulated current limit signal to control a transfer of energy from an input of a power converter to an output of the power converter. The current limit generator is coupled to generate a current limit signal. The jitter modulator is coupled to generate a jitter signal for jittering a switching period of the drive signal without an oscillator. The arithmetic operator circuit is coupled to receive the current limit signal and the jitter signal and is coupled to generate a modulated current limit signal in response to the current limit signal and the jitter signal.