Abstract: An EMI emission suppressing system, apparatus and method that enables the EMI produced by high frequency switching of a switching circuit to be suppressed via the transfer of the higher order harmonic emissions to a frequency range below the standard EMI bandwidth of less than 150 KHz by applying low frequency modulation or jitter into the feedback of a switching signal of the switching circuit. The EMI suppression is achieved with minimal added ripple on the output signal of the switching circuit by using discontinuous modulations in the form of only applying the low frequency modulation when the switch or higher order harmonic producing element of the switching circuit is accessing, or drawing power from, the main power supply.

Abstract: A controller for use with a power converter and method of operating the same. In one embodiment, the controller includes a transformer voltage sensing circuit configured to produce a preliminary bus voltage sample. The controller also includes a frequency correction circuit coupled to the transformer voltage sensing circuit and configured to correct the preliminary bus voltage sample to produce an estimate of an internal bus voltage of the power converter.

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: A controller for a power converter and method of operating the same. In one embodiment, the controller includes a current-sense device couplable in series with switched terminals of power switches of interleaved switching regulators and configured to produce a current-sense signal. The controller also includes an error amplifier configured to produce an error signal as a function of a characteristic of the power converter. The controller also includes a duty-cycle controller configured to sample the current-sense signal at mid-points of duty cycles of the power switches and regulate the characteristic as a function of the error signal and the current-sense signal.

Abstract: A power converter including an inductor-inductor-capacitor stage and method of operating the same. In one embodiment, the power converter includes an inductor-inductor-capacitor (LLC) stage coupled to an input of said power converter. The power converter also includes a controller configured to control a switching frequency of the LLC stage as a function of an input voltage of the power converter.

Abstract: A controller for use with a power converter and method of operating the same. In one embodiment, the controller includes a light emitting diode string controller configured to receive a dimmer signal and control a level of current in a light emitting diode string in response to the dimmer signal. The controller also includes a power converter controller configured to receive the dimmer signal and control an output current of the power converter that is a multiple of the level of current in the light emitting diode string.

Abstract: A magnetic device and power converter employing the same. In one embodiment, the magnetic device includes a first L-core segment including a first leg and a second leg extending therefrom, and an opposing second L-core segment including a first leg and a second leg extending therefrom. The magnetic device also includes a winding formed around at least one of the first leg and the second leg of the first L-core segment or the second L-core segment.

Abstract: A magnetic device and power converter employing the same. In one embodiment, the magnetic device includes a first L-core segment including a first leg and a second leg extending therefrom, and an opposing second L-core segment including a first leg and a second leg extending therefrom. The magnetic device also includes a winding formed around at least one of the first leg and the second leg of the first L-core segment or the second L-core segment.

Abstract: A magnetic device and power converter employing the same. In one embodiment, the magnetic device includes a first L-core segment including a first leg and a second leg extending therefrom, and an opposing second L-core segment including a first leg and a second leg extending therefrom. The magnetic device also includes a winding formed around at least one of the first leg and the second leg of the first L-core segment or the second L-core segment.

Abstract: A magnetic device and power converter employing the same. In one embodiment, the magnetic device includes a first L-core segment including a first leg and a second leg extending therefrom, and an opposing second L-core segment including a first leg and a second leg extending therefrom. The magnetic device also includes a winding formed around at least one of the first leg and the second leg of the first L-core segment or the second L-core segment.

Abstract: A controller for a power converter and method of operating the same. In one embodiment, the controller includes an inductor-inductor-capacitor (“LLC”) controller configured to receive an error signal from an error amplifier to control a switching frequency of an LLC stage of the power converter to regulate an output voltage thereof. The controller also includes a power factor correction (“PFC”) controller configured to control a bus voltage produced by a PFC stage of the power converter and provided to the LLC stage so that an average switching frequency thereof is substantially maintained at a desired switching frequency.

Abstract: A start-up circuit for a power adapter and method of operating the same. In one embodiment, the power adapter includes a start-up circuit configured to provide an initial bias voltage for the power adapter. The power adapter also includes a crowbar circuit configured to turn on the start-up circuit upon loss of an ac mains voltage supplied to the power adapter.