Abstract: A power converter employing a controller configured to increase a dead time between conduction periods of first and second power switches therein and method of operating the same. In one embodiment, the power converter includes first and second power switches coupled to an input thereof, and a sensor configured to provide a sensed signal representative of at least one of a current level and a power level of the power converter. The power converter also includes a controller configured to increase a dead time between conduction periods of the first and second power switches when the sensed signal indicates a decrease of at least one of the current level and the power level of the power converter.

Abstract: A power converter including a power switch, a controller for controlling a switching frequency thereof, and a magnetic device with a non-uniform gap. In one embodiment, the power converter includes a power switch and a magnetic device coupled to the power switch and having a non-uniform gap. The power converter also includes a controller having a detector configured to sense a condition representing an output power of the power converter. A control circuit of the controller is configured to control a switching frequency of the power switch as a function of the condition and control a duty cycle of the power switch to regulate an output characteristic of the power converter.

Abstract: A regulated power apparatus is provided. The apparatus includes an input power converting circuit configured for receiving a rectified voltage and for generating an increased voltage. An intermediate power regulating circuit generates a regulated voltage that has a lower voltage than a minimum output voltage of the input power converting circuit. The intermediate power regulating circuit is coupled to receive the increased voltage. An output power converting circuit is coupled with the intermediate power regulating circuit. The output power converting circuit receives the regulated voltage and generates an output voltage that is lower than the regulated voltage. The output power converting circuit comprises a buck converter configured to operate at a fixed duty cycle. A regulation circuit is coupled with the intermediate power regulating circuit and coupled with the output power converting circuit.

Abstract: A resonant power converter draws current from a source that provides a supply current. Multiple quasi-resonant converters are interleaved and each quasi-resonant converter receives the supply current and forms a phase-shifted current according to drive signals supplied by a controller. Each phase-shifted current includes a dead-time delay and is phase-shifted relative to the other phase-shifted currents. The dead-time delay is determined as a time value within a calculated dead-time delay range having a dead-time delay minimum and a dead-time delay maximum. The outputs of each quasi-resonant converter are added together thereby reducing the AC components of current. Two, three, or four quasi-resonant power converters can be interleaved, each forming phase-shifted currents that are phase-shifted relative to the other phase-shifted currents.

Abstract: A regulated power supply apparatus and method are provided. The apparatus includes a converter circuit for generating a regulated voltage signal. The converter circuit includes a first switching circuit and a second switching circuit both coupled with an output circuit. A first and a second transformer include a first and a second secondary, which are coupled with each other in series or alternatively, coupled with each other in parallel. An input rectifier circuit is coupled with the first and the second switching circuit. The input rectifier circuit is configured for receiving an AC input voltage and for generating a rectified voltage. The input rectifier circuit includes controlled switches and a first and second configuration of a bridge rectifier that couples the first and second switching circuits in series or parallel depending if the AC input power signal is “high-line” or “low-line.” A controller circuit is provided for enabling either the first configuration or the second configuration.

Abstract: A regulated power apparatus is provided. The apparatus includes an input power converting circuit configured for receiving a rectified voltage and for generating an increased voltage. An intermediate power regulating circuit generates a regulated voltage that has a lower voltage than a minimum output voltage of the input power converting circuit. The intermediate power regulating circuit is coupled to receive the increased voltage. An output power converting circuit is coupled with the intermediate power regulating circuit. The output power converting circuit receives the regulated voltage and generates an output voltage that is lower than the regulated voltage. The output power converting circuit comprises a buck converter configured to operate at a fixed duty cycle. A regulation circuit is coupled with the intermediate power regulating circuit and coupled with the output power converting circuit.

Abstract: A regulated power factor corrected power supply apparatus is provided. The apparatus includes an input rectifier circuit for receiving an input AC voltage and outputting a full-wave rectified DC voltage. A single-stage isolated buck-type converter is coupled with the input circuit. The converter circuit comprises an isolated buck-type converter circuit including an isolation transformer. An output rectifier and semiconductor tap switch are coupled to a secondary winding of the isolation transformer. The tap switch couples a larger portion of the secondary winding to an output bulk capacitor during the portions of the input sinewave half-cycle, which are low in amplitude. The tap switch enables the single-stage isolation buck-type converter to operate over a much larger portion of the input sinewave, but also allows the converter to operate at high-efficiency over the majority of the input sinewave.

Abstract: An apparatus for generating a compensation signal for a power converter where the second harmonic ripple on the voltage bus is substantially removed from the compensation signal. The apparatus comprises a frequency-locked clock generator, a bus voltage data generator, a stack, and a compensation signal generator. The frequency-locked clock is coupled to the power converter voltage bus that contains harmonics of the AC line frequency. The clock generator frequency locks to the second harmonic of the AC line frequency and creates a system clock which is used for the synchronous operations throughout the apparatus. The bus-voltage data generator inputs a power converter scaled-bus voltage, generates bus-voltage data at a sampling rate which is determined by the coupled system clock. The output of the bus-voltage generator is input into a stack.

Abstract: A power converter employing a control system configured to make multiple functional use of a circuit node therein and method of operating the same. In one embodiment, the power converter includes a power train including at least one power switch. The power converter also includes a control system including an opto-isolator circuit, including a resistor, configured to receive an output signal from the power converter and provide a feedback signal to a feedback node for the control system to provide a switch control signal for the at least one power switch. The control system also includes a current source configured to produce multiple voltage levels at the feedback node in accordance with the resistor, thereby enabling multiple functional uses of the feedback node.

Abstract: Generally, a DC power filter and its associated components are presented herein. The DC power filter may operate in a telecommunications chassis between one or more electrical sources and one or more loads. A common mode noise shunt may be included to shunt noise from more than one of the electrical sources or loads together. Additionally, the DC power filter may include protection circuitry that is coupled to more than one of the electrical sources. The protection circuitry may include a combination of diodes and other transient voltage suppression devices.

Abstract: A regulated power supply apparatus and method are provided. The apparatus includes a converter circuit for generating a regulated voltage signal. The converter circuit includes a first switching circuit and a second switching circuit both coupled with an output circuit. A first and a second transformer include a first and a second secondary, which are coupled with each other in series or alternatively, coupled with each other in parallel. An input rectifier circuit is coupled with the first and the second switching circuit. The input rectifier circuit is configured for receiving an AC input voltage and for generating a rectified voltage. The input rectifier circuit includes controlled switches and a first and second configuration of a bridge rectifier that couples the first and second switching circuits in series or parallel depending if the AC input power signal is “high-line” or “low-line.” A controller circuit is provided for enabling either the first configuration or the second configuration.

Abstract: A power converter employing a controller configured to increase a dead time between conduction periods of first and second power switches therein and method of operating the same. In one embodiment, the power converter includes first and second power switches coupled to an input thereof, and a sensor configured to provide a sensed signal representative of at least one of a current level and a power level of the power converter. The power converter also includes a controller configured to increase a dead time between conduction periods of the first and second power switches when the sensed signal indicates a decrease of at least one of the current level and the power level of the power converter.

Abstract: A power adapter including a power reducer for no-load or light load applications and method of operating the same. In one embodiment, the power adapter includes a capacitor coupled to an input of the power adapter, and a bleeder switch coupled in parallel with the capacitor. The power adapter also includes a detection circuit configured to sense an ac mains voltage at the input of the power adapter and turn on the bleeder switch upon detection of a loss of the ac mains voltage. In addition to or in lieu of, the power adapter may include a power converter, and a disconnect switch configured to disconnect the ac mains voltage from the power converter in response to a signal from a load.

Abstract: A power converter including a power switch, a controller for controlling a switching frequency thereof, and a magnetic device with a non-uniform gap. In one embodiment, the power converter includes a power switch and a magnetic device coupled to the power switch and having a non-uniform gap. The power converter also includes a controller having a detector configured to sense a condition representing an output power of the power converter. A control circuit of the controller is configured to control a switching frequency of the power switch as a function of the condition and control a duty cycle of the power switch to regulate an output characteristic of the power converter.

Abstract: Generally, a DC/DC converter and its associated devices and processes are presented herein. The DC/DC converter may be a switched mode converter that includes a plurality of switching devices that couple between the first and second power supply rails. A transformer is coupled to the switching devices such that the switching devices exchange electrical energy through the transformer. A rectifier is coupled to the transformer to rectify the waveform from the transformer into a substantially DC output. The DC/DC converter also includes clamp diodes to relieve voltage stress on rectifier diodes. Resistors may be coupled in series with the clamp diodes to reduce a reset time of the DC/DC converter and thereby prevent catastrophic failure of the power supply during load transients. Additionally, the DC/DC converter may be configured with a power outage detection device that monitors gate drive signals of the converter.

Abstract: Generally, a DC power filter and its associated components are presented herein. The DC power filter may operate in a telecommunications chassis between one or more electrical sources and one or more loads. A common mode noise shunt may be included to shunt noise from more than one of the electrical sources or loads together. Additionally, the DC power filter may include protection circuitry that is coupled to more than one of the electrical sources. The protection circuitry may include a combination of diodes and other transient voltage suppression devices.

Abstract: An apparatus for generating a compensation signal for a power converter where the second harmonic ripple on the voltage bus is substantially removed from the compensation signal. The apparatus comprises a frequency-locked clock generator, a bus voltage data generator, a stack, and a compensation signal generator. The frequency-locked clock is coupled to the power converter voltage bus that contains harmonics of the AC line frequency. The clock generator frequency locks to the second harmonic of the AC line frequency and creates a system clock which is used for the synchronous operations throughout the apparatus. The bus-voltage data generator inputs a power converter scaled-bus voltage, generates bus-voltage data at a sampling rate which is determined by the coupled system clock. The output of the bus-voltage generator is input into a stack.

Abstract: An AC-to-DC power converter configured to provide power factor correction and a single isolated low-voltage output. The power converter includes a single-stage resonant power converter including an isolation transformer, a resonant tank, a rectifier, and a bulk storage capacitor coupled to an output of the isolation transformer. In typical applications, at least one non-isolated power converter is coupled to the output of the single-stage isolated power factor correction converter.

Abstract: A regulated power factor corrected power supply apparatus is provided. The apparatus includes an input rectifier circuit for receiving an input AC voltage and outputting a full-wave rectified DC voltage. A single-stage isolated buck-type converter is coupled with the input circuit. The converter circuit comprises an isolated buck-type converter circuit including an isolation transformer. An output rectifier and semiconductor tap switch are coupled to a secondary winding of the isolation transformer. The tap switch couples a larger portion of the secondary winding to an output bulk capacitor during the portions of the input sinewave half-cycle, which are low in amplitude. The tap switch enables the single-stage isolation buck-type converter to operate over a much larger portion of the input sinewave, but also allows the converter to operate at high-efficiency over the majority of the input sinewave.

Abstract: Generally, a DC/DC converter and its associated devices and processes are presented herein. The DC/DC converter may be a switched mode converter that includes a plurality of switching devices that couple between the first and second power supply rails. A transformer is coupled to the switching devices such that the switching devices exchange electrical energy through the transformer. A rectifier is coupled to the transformer to rectify the waveform from the transformer into a substantially DC output. The DC/DC converter also includes clamp diodes to relieve voltage stress on rectifier diodes. Resistors may be coupled in series with the clamp diodes to reduce a reset time of the DC/DC converter and thereby prevent catastrophic failure of the power supply during load transients. Additionally, the DC/DC converter may be configured with a power outage detection device that monitors gate drive signals of the converter.