Abstract: A circuit includes a zero current detector (ZCD) circuit that senses an inductor current of an inductor and generates signal pulses indicating when an increasing cycle of the inductor current crosses a predetermined current value and when a decreasing cycle of the inductor current crosses the predetermined current value. A sync control provides a control signal specifying one of the signal pulses corresponding to the increasing or decreasing cycle of the inductor current. A sync selector circuit generates a sync pulse representing the signal pulse from the ZCD in response to the control signal. The sync pulse triggers a timing adjustment for a switch device.

Abstract: A multiple-output integrated power factor correction system includes, for example, a processor that is formed in a substrate and is arranged to monitor each voltage output of two or more output stages of a power supply and in response to generate an individual voltage error signal for each monitored output stage. A combined output voltage error signal is generated in response to each of the individual voltage error signals. The voltage input to the power supply and the total inductor current of the power supply are monitored and used to generate a combined output voltage control signal in response to the monitored input voltage total inductor current as well as the combined output voltage error control signal. Each individual output voltage control signal for each monitored output stage is generated in response to each of the respective generated individual voltage error signals.

Abstract: A multiple-output integrated power factor correction system includes, for example, a processor that is formed in a substrate and is arranged to monitor each voltage output of two or more output stages of a power supply and in response to generate an individual voltage error signal for each monitored output stage. A combined output voltage error signal is generated in response to each of the individual voltage error signals. The voltage input to the power supply and the total inductor current of the power supply are monitored and used to generate a combined output voltage control signal in response to the monitored input voltage total inductor current as well as the combined output voltage error control signal. Each individual output voltage control signal for each monitored output stage is generated in response to each of the respective generated individual voltage error signals.

Abstract: A circuit includes a zero current detector (ZCD) circuit that senses an inductor current of an inductor and generates signal pulses indicating when an increasing cycle of the inductor current crosses a predetermined current value and when a decreasing cycle of the inductor current crosses the predetermined current value. A sync control provides a control signal specifying one of the signal pulses corresponding to the increasing or decreasing cycle of the inductor current. A sync selector circuit generates a sync pulse representing the signal pulse from the ZCD in response to the control signal. The sync pulse triggers a timing adjustment for a switch device.

Abstract: An envelope tracking power supply has a multiple-output DC/DC converter, having an alternating current generating portion and a full rectifying portion. The alternating current generating portion to receive an input voltage and operate at zero voltage switching. A full rectifying portion includes at least one secondary winding and one voltage doubler output. each having a first transistor, and a second transistor, used as rectifier devices to allow currents to flow bi-directionally and sink and source the currents from and to output capacitors to keep their voltage balance. A switch bank selects a desired voltage from series connected capacitors and connects it to an output filter. The switch bank receives an envelope tracking command from the voltage selector and provides a step voltage to the output. The output voltage is changed at switching speed to track a high bandwidth envelope signal.

Abstract: Power factor correction (PFC) apparatus, controllers, and methods for operating bridgeless totem pole power factor correction converters in which AC input voltage polarity is detected for designation of active and freewheeling switches of the totem pole circuit, a nominal freewheeling switch on-time is determined according to a Volt×Second balance relationship, and the voltage across the designated active switch is sensed and used to selectively modify or offset the nominal freewheeling switch on-time to provide a computed freewheeling switch on-time for the next switching cycle to facilitate zero voltage switching of the active switch.

Abstract: A digital power supply and power supply controller are presented, including a voltage control loop and a current control loop, with a controller for pulse width modulating a switching power supply according to a voltage control loop duty cycle output or a current control loop duty cycle output, in which the controller selectively presets the voltage control loop duty cycle output to a predetermined value before switching from current loop control to voltage loop control and/or inhibits increase in a voltage loop integrator value during current loop control to mitigate voltage overshoot.

Abstract: Disclosed is a family of new DC/DC converters and a new control method. The converter comprises two bridge inverters, two full-wave rectification circuits and a current-doubler filter. Each inverter is able to generate a symmetrical and isolated AC output voltage. Phase-shift control is employed to control the phase difference between the two bridge inverters. By shifting the phase, the converter changes the two inverters' output voltage overlapping area to regulate its output voltage. The bridge inverters always operate at 50% duty cycle, like an open loop Bus Converter, to achieve wide-range zero voltage switching and eliminate circulating current for normal operation. For low output voltage regulation and soft start, Pulse Width Modulation (PWM) control is used. The converters and the control method improve power conversion efficiency, maximize magnetic component utilization, reduce semiconductor stress and decrease EMI emission.

Abstract: A multiple-output integrated power factor correction system includes, for example, a processor that is formed in a substrate and is arranged to monitor each voltage output of two or more output stages of a power supply and in response to generate an individual voltage error signal for each monitored output stage. A combined output voltage error signal is generated in response to each of the individual voltage error signals. The voltage input to the power supply and the total inductor current of the power supply are monitored and used to generate a combined output voltage control signal in response to the monitored input voltage total inductor current as well as the combined output voltage error control signal. Each individual output voltage control signal for each monitored output stage is generated in response to each of the respective generated individual voltage error signals.

Abstract: Power factor correction (PFC) apparatus, controllers, and methods for operating bridgeless totem pole power factor correction converters in which AC input voltage polarity is detected for designation of active and freewheeling switches of the totem pole circuit, a nominal freewheeling switch on-time is determined according to a Volt×Second balance relationship, and the voltage across the designated active switch is sensed and used to selectively modify or offset the nominal freewheeling switch on-time to provide a computed freewheeling switch on-time for the next switching cycle to facilitate zero voltage switching of the active switch.

Abstract: A method of operating a power factor correction (PFC) circuit and a corresponding power factor correction circuit include determining an adaptive switching frequency of the PFC circuit related to a current of the boost inductor of the PFC circuit, and operating the PFC circuit at a light load based on the adaptive switching frequency.

Abstract: Methods and circuits for balancing current in a transformer are disclosed herein. An embodiment of the method includes sensing the magnitude and direction of current flow through the primary side of the transformer. The magnitude of current flowing in a first direction is compared to the magnitude of current flowing in a second direction through the primary side of the transformer. An AC signal driving the primary side of the transformer is adjusted so that the current flow in the first direction is substantially the same as current flow in the second direction.

Abstract: In a first aspect, a control circuit is provided for use with a switch-mode power stage that provides an output voltage signal and an output current signal at an output power. The switch-mode power stage has a nominal voltage, a nominal current, a maximum current, an output power and a maximum power. The control circuit includes a voltage control loop and a current control loop, and the control circuit uses the voltage control loop to provide voltage mode control if the output current signal is greater than or equal to the nominal current and less than the maximum current, wherein the output power is substantially constant. Numerous other aspects are also provided.

Abstract: A DC-to-DC converter has a leading full-bridge inverter and a lagging full-bridge inverter for receiving a DC input and producing respective AC output voltages. A full-wave rectifier circuit rectifies the AC output voltages to produce a rectified output voltage, which is filtered by a current doubling output filter circuit to produce a DC output voltage. A master phase-shift controller and a slave phase-shift controller respectively provide first and second control signals to the leading full-bridge inverter and third and fourth control signals to the lagging full-bridge inverter to regulate the DC output voltage by changing a phase of the second and fourth control signals with respect to the first and third control signals below a predetermined DC output voltage, and by changing a phase of the third and fourth control signals with respect to the first and second control signals above the predetermined threshold.

Abstract: A controller for a DC/DC converter can include a first error analog to digital converter (EADC) configured to detect a primary voltage from a secondary side of a transformer and generate a first error signal corresponding to the primary voltage. The first error signal is generated based on a comparison between a first reference voltage and the detected primary voltage. A first accelerator can be configured to process the first error signal and generate a first compensation signal that is a primary voltage variation signal used for feedforward control. A second EADC and a second accelerator can be configured to provide a output voltage feedback control. A compensation signal of the first accelerator can be used to scale the second accelerator output to facilitate fast feedforward control.

Abstract: The present invention provides a DC/DC converter for use with a DC input signal. The DC/DC converter includes a control signal generator, a primary and a secondary side, a voltage generating portion, a threshold voltage providing portion and a feedback signal generator. The control signal generator can control the primary side and the secondary side. The voltage generating portion can generate a surge voltage based a control signal from the control signal generator. The threshold voltage providing portion can generate a threshold voltage. The feedback signal generator can generate a feedback signal based on the surge voltage and the threshold voltage. The control signal generator can further modify control of one of the primary and secondary sides based on the feedback signal.

Abstract: A digital power supply and power supply controller are presented, including a voltage control loop and a current control loop, with a controller for pulse width modulating a switching power supply according to a voltage control loop duty cycle output or a current control loop duty cycle output, in which the controller selectively presets the voltage control loop duty cycle output to a predetermined value before switching from current loop control to voltage loop control and/or inhibits increase in a voltage loop integrator value during current loop control to mitigate voltage overshoot.

Abstract: The present invention provides a DC/DC converter for use with a DC input signal. The DC/DC converter includes a control signal generator, a primary and a secondary side, a voltage generating portion, a threshold voltage providing portion and a feedback signal generator. The control signal generator can control the primary side and the secondary side. The voltage generating portion can generate a surge voltage based a control signal from the control signal generator. The threshold voltage providing portion can generate a threshold voltage. The feedback signal generator can generate a feedback signal based on the surge voltage and the threshold voltage. The control signal generator can further modify control of one of the primary and secondary sides based on the feedback signal.

Abstract: Methods and circuits for balancing current in a transformer are disclosed herein. An embodiment of the method includes sensing the magnitude and direction of current flow through the primary side of the transformer. The magnitude of current flowing in a first direction is compared to the magnitude of current flowing in a second direction through the primary side of the transformer. An AC signal driving the primary side of the transformer is adjusted so that the current flow in the first direction is substantially the same as current flow in the second direction.