Abstract: Apparatus and methods for sequencing outputs in a multi-output power converter system are disclosed herein. During start-up multiple CC/CV outputs may be sequenced so that energy is first provided to a highest voltage secondary output and subsequently provided to a lowest voltage secondary output. Additionally, control may be exerted so as to concurrently and monotonically increase voltages during at least part of the start-up transient; and concurrent control may be further implemented using control circuitry and a variable reference generator. In some embodiments a variable reference may be generated from a capacitor voltage.

Abstract: A controller for a multiple output power converter, including an error amplifier configured to generate an error signal based on a difference between an output signal of a multiple output power converter and a reference signal. A switch request circuit is configured to generate a request signal in response to the error signal. The switch request circuit is further configured to control a switching of a power switch of the multiple output power converter to transfer energy from an input of the multiple output power converter to an output of the multiple output power converter. A power limit fault circuit is configured to receive the request signal and the error signal, the power limit fault circuit further configured to generate a first fault signal in response to detection of an output overload or short circuit.

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 power converter includes a primary winding and multiple output windings to provide multiple independently controlled and regulated outputs with a common return line. The outputs are coupled to independently regulate constant current, constant voltage, or both constant current and constant voltage outputs. A secondary control block is coupled to control a synchronous rectifier switch coupled to the common return line to synchronize switching with a primary side power switch to provide complementary conduction of the primary winding and the multiple output windings. A plurality of controlled power pulse switches is coupled to the multiple output windings. A request of a power pulse from each of the outputs is transferred through the secondary control block to a primary switch control block to turn on the primary side power switch to transfer a power pulse to the multiple output windings and through controlled power pulse switches to the outputs.

Abstract: A controller for use in a power converter includes a comparator that receives an output signal representative of an output voltage of the power converter. The comparator generates a constant voltage signal in response to a comparison of the output signal and a reference signal. A switch request circuit receives the constant voltage signal and a fault signal. The switch request circuit generates a request signal in response to the constant voltage signal and the fault signal to control switching of a power switch of the power converter to control a transfer of energy from an input of the power converter to the output of the power converter. A power limit fault circuit receives the request signal. The power limit fault circuit generates the fault signal to indicate a fault existence in the power converter in response to a rate of consecutive request pulses greater than a threshold.

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 power converter includes a primary winding and multiple output windings to provide multiple independently controlled and regulated outputs with a common return line. The outputs are coupled to independently regulate constant current, constant voltage, or both constant current and constant voltage outputs. A secondary control block is coupled to control a synchronous rectifier switch coupled to the common return line to synchronize switching with a primary side power switch to provide complementary conduction of the primary winding and the multiple output windings. A plurality of controlled power pulse switches is coupled to the multiple output windings. A request of a power pulse from each of the outputs is transferred through the secondary control block to a primary switch control block to turn on the primary side power switch to transfer a power pulse to the multiple output windings and through controlled power pulse switches to the outputs.

Abstract: Apparatus and methods for sequencing outputs in a multi-output power converter system are disclosed herein. During start-up multiple CC/CV outputs may be sequenced so that energy is first provided to a highest voltage secondary output and subsequently provided to a lowest voltage secondary output. Additionally, control may be exerted so as to concurrently and monotonically increase voltages during at least part of the start-up transient; and concurrent control may be further implemented using control circuitry and a variable reference generator. In some embodiments a variable reference may be generated from a capacitor voltage.

Abstract: A method of dynamically adjusting a storage time of a bipolar junction transistor (BJT) in a switched mode power converter during a switching cycle includes generating a storage time reference signal responsive to an input voltage signal. A collector off signal is generated responsive to a comparison of a current sense signal to a collector off reference threshold signal. The current sense signal is representative of a switch current of the BJT. A base off reference threshold signal is generated responsive to the storage time reference signal and the collector off signal. A base off signal is generated responsive to a comparison of the current sense signal and the base off reference threshold signal. Charging of a base terminal of the BJT is discontinued responsive to the base off signal, and the base terminal of the BJT is discharged responsive to the collector off signal.

Abstract: A controller for use in a power converter with multiple outputs includes a discharge detect circuit coupled to receive a voltage signal from a transformer winding of the power converter to output a discharge signal in response to the voltage signal. A multi-output signal process and interface block is coupled to output request signals to the output selection drive and idle ring visibility logic circuit. An output selection drive and idle ring visibility logic circuit is coupled to receive the discharge signal from the discharge detect circuit and the output request signals from the multi-output signal process and interface block. An idle ring detection circuit is coupled to one of the plurality of output switches and coupled to output an idle ring output signal to generate a next request pulse.

Abstract: A dimmer interface circuit for reducing ringing on a drive signal to a lighting device. The dimmer interface circuit controls brightness of the lighting device and receives a brightness control voltage from a dimmer circuit. The dimmer interface includes a voltage converter and a charge store, which is coupled to receive charge from an inductive component to convert the brightness control voltage to the converter output voltage. The dimmer interface circuit also includes control circuitry to control the voltage converter such that a difference between the brightness control voltage and the converter output voltage at a time of transition of the brightness control voltage is closer to a target voltage difference.

Abstract: A controller for a power converter includes a driver circuit that generates a control signal to switch a power switch in response to an output, and a control circuit that controls the switching of the power switch. The control circuit includes a storage time reference circuit generates a storage time reference signal responsive to an input. A first comparator generates a collector off signal in response to a comparison of a switch current sense signal and a collector off reference signal. A storage time regulator circuit generates a base off reference signal in response to the storage time reference signal and the collector off signal. A second comparator generates a base off signal in response to a second comparison of the switch current sense signal and the base off reference signal. The driver circuit is coupled to discontinue and start charging a base terminal of the BJT power switch.

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: An ac-dc power supply includes a dc-dc converter coupled to an input of the ac-dc power supply. The input of the ac-dc power supply is coupled to receive an ac input voltage and an ac input current. The dc-dc converter includes a regulated output and a reservoir output. A controller is coupled to receive sense signals from the dc-dc converter. The controller is coupled to control the dc-dc converter to regulate the regulated output in response to the sense signals. The controller is further coupled to control a waveform of the ac input current to have a substantially same shape as a waveform of the ac input voltage. A regulator circuit is coupled to the regulated output and the reservoir output. The controller is coupled to the regulator circuit to control a transfer of energy from the reservoir output to the regulated output through the regulator circuit.

Abstract: A controller for use in a two-stage power supply is coupled to control switching of a switching element to regulate a transfer of energy from an input to an output of a flyback converter. The controller activates a boost switching element during a first interval in each line half cycle of an input voltage to boost an output voltage at an output of a boost-bypass converter. The controller deactivates the boost switching element during a second interval in each line half cycle such that the output voltage of the boost-bypass converter drops towards the input voltage during the second interval while the output voltage of the boost-bypass converter is greater than the input voltage. The controller controls the output voltage to follow the input voltage during a third interval of each line half cycle while the boost switching element remains deactivated and the input and output voltages are substantially equal.

Abstract: A power converter includes a primary winding and multiple output windings to provide multiple independently controlled and regulated outputs with a common return line. The outputs are coupled to independently regulate constant current, constant voltage, or both constant current and constant voltage outputs. A secondary control block is coupled to control a synchronous rectifier switch coupled to the common return line to synchronize switching with a primary side power switch to provide complementary conduction of the primary winding and the multiple output windings. A plurality of controlled power pulse switches is coupled to the multiple output windings. A request of a power pulse from each of the outputs is transferred through the secondary control block to a primary switch control block to turn on the primary side power switch to transfer a power pulse to the multiple output windings and through controlled power pulse switches to the outputs.

Abstract: A controller for use in a two-stage power supply is coupled to control switching of a switching element to regulate a transfer of energy from an input to an output of a flyback converter. The controller activates a boost switching element during a first interval in each line half cycle of an input voltage to boost an output voltage at an output of a boost-bypass converter. The controller deactivates the boost switching element during a second interval in each line half cycle such that the output voltage of the boost-bypass converter drops towards the input voltage during the second interval while the output voltage of the boost-bypass converter is greater than the input voltage. The controller controls the output voltage to follow the input voltage during a third interval of each line half cycle while the boost switching element remains deactivated and the input and output voltages are substantially equal.

Abstract: A boost-bypass converter includes a boost inductor coupled between an input and an output of the boost-bypass converter. A bypass diode is coupled between the input the output of the boost-bypass converter. A boost switching element is coupled to the boost inductor, and is coupled to be activated during a first interval in each line half cycle of an input voltage to boost an output voltage at the output of the boost-bypass converter. The boost switching element is coupled to be deactivated during a second interval in said each line half cycle such that the output voltage drops towards the input voltage. The output voltage is coupled to follow the input voltage during a third interval in said each line half cycle of the input voltage. Energy is transferred between the input and the output of the boost-bypass converter through the bypass diode during the third interval.

Abstract: An ac-dc power supply includes a dc-dc converter coupled to an input of the ac-dc power supply. The input of the ac-dc power supply is coupled to receive an ac input voltage and an ac input current. The dc-dc converter includes a regulated output and a reservoir output. A controller is coupled to receive sense signals from the dc-dc converter. The controller is coupled to control the dc-dc converter to regulate the regulated output in response to the sense signals. The controller is further coupled to control a waveform of the ac input current to have a substantially same shape as a waveform of the ac input voltage. A regulator circuit is coupled to the regulated output and the reservoir output. The controller is coupled to the regulator circuit to control a transfer of energy from the reservoir output to the regulated output through the regulator circuit.

Abstract: A controller for use in a power converter includes a first edge detection circuit that receives a first input sense signal representative of an input of the power converter coupled to a dimmer circuit, and generates a first edge detection signal in response to the first input sense signal. A shaping circuit receives the first edge detection signal from the first edge detection circuit. The shaping circuit generates a first shape signal in response to the first edge detection signal. A drive circuit receives the first shape signal and a feedback signal representative of an output of the power converter. The drive circuit generates the drive signal in response to the feedback signal to control switching of a power switch of the power converter. The drive circuit switches the power switch in a first higher current mode for a first duration in response to the first shape signal.