Lucent Technologies Inc.

Other

Tyco Electronics Power Systems, Inc.

Wayne C Bowman

Van A Niemela

Allen Frank Rozman

Ashraf W Lotfi

Rui Liu

Mark E Jacobs

Chris Morrow Young

Shiaw-Jong Steve Chen

Matthew Anthony Wilkowski

Feng Lin

Thomas G Wang

Shiaw-Jong Stee Chen

The present invention provides an integrated controller for use with a power supply employing a pulse width modulator and a method of operation thereof. In one embodiment, the integrated controller includes a primary control circuit configured to provide a control signal to the pulse width modulator. Additionally, the integrated controller includes a feedback circuit configured to monitor an output signal of the pulse width modulator and to modify the control signal thereby enabling a substantially monotonic increase in an output voltage of the power supply output voltage during a non-steady state period of operation thereof.

Integrated controller, method of operation thereof and power supply employing the same

A method for determining the effect of load impedance on the magnitude and phase of loop gain of a power converter apparatus to aid in predicting stability of the converter apparatus under various operating conditions. The converter apparatus has an open-loop output impedance and provides an output signal to an output locus. The method comprises the steps of: (a) vectorally measuring a first loop gain of the converter apparatus with a first load impedance connected with the output locus, to record phase and gain of the first loop gain for a plurality of frequencies; (b) vectorally measuring open loop output impedance as a function of frequency of the converter apparatus, to record phase and gain of the open loop output impedance for a plurality of frequencies; (c) vectorally measuring the first load impedance as a function of frequency of the converter apparatus, to record phase and gain of the first load impedance for a plurality of frequencies; (d) calculating a first load distribution factor using the first load impedance and the open-loop output impedance; the calculating being effected in vectoral manner to record magnitude and phase of the first load distribution factor for a plurality of frequencies; (e) selecting a second impedance load with an output voltage sense point, the second impedance load being representable by a network of at least one resistor and at least one capacitor or inductor, the output voltage sense point being situated at a selected node of the network; (f) calculating a second load distribution factor for the second impedance load using the open-loop output impedance and the second impedance load; the calculating being effected in vectoral manner to record magnitude and phase of the impedance-loop load distribution factor for a plurality of frequency values; and (g) calculating a second loop gain using the first loop gain, the first loop load distribution factor and the second loop load distribution factor; the calculating being effected in vectoral manner to record magnitude and phase of the impedance-load gain for a plurality of frequency values.

Method for predicting stability characteristics of power supplies

A system and method for reducing a DC magnetic flux bias in a transformer and a power converter employing the system or the method. The power converter has a full bridge switching circuit coupled across a primary winding of a transformer and a hybridge rectifier circuit coupled across a secondary winding of the transformer. The transformer is subject to the DC magnetic flux bias as a result of an imbalance in the hybridge rectifier circuit. In one embodiment, the system includes: (1) a sensor configured to develop a signal representing the DC magnetic flux bias in the transformer; and (2) a controller, coupled to the sensor, configured to operate the full bridge switching circuit as a function of the signal thereby to reduce the DC magnetic flux bias.

System and method for reducing a DC magnetic flux bias in a transformer and power converter employing the same

A drive circuit for a converter and a method of driving a converter. The converter includes an inverter and a synchronous rectifier. The drive circuit includes: (1) a modulation circuit for generating a drive waveform for controlling the inverter and the synchronous rectifier employing a negative feedback loop, (2) a modification circuit, coupled to the modulation circuit, for sensing an operating condition of the converter and shifting a portion of the drive waveform as a function of the operating condition, the modification circuit thereby creating a variable drive waveform from the drive waveform without employing negative feedback and (3) a transmission circuit, coupled to the modification circuit, for applying the variable drive waveform to the converter, thereby allowing a variable nonconcurrent change in state of the inverter and the synchronous rectifier according to the function of the operating condition.

Power converter adaptively driven

A method of mounting a power semiconductor die on a substrate, a package for the die and a power supply including the package. The die has a first power terminal on a first surface thereof and a second power terminal on an opposing second surface thereof. The method including the steps of: (1) forming an electrically-conductive, mechanical bond between the first surface and a first location on the substrate, the mechanical bond electrically coupling the first power terminal to the substrate and (2) soldering an elongated electrically conductive strap to the second surface and a second location on the substrate, the conductive strap composed of a material having an electrical resistivity at most about 5.0.times.10.sup.-8 ohm-meters (.OMEGA.-m) and forming a low impedance path between the second power terminal and the second location.

Method of mounting a power semiconductor die on a substrate

A power converter having an input and output and a method of operating the power converter. In one embodiment, the power converter includes a power transformer having primary and secondary windings and a power switch coupled to the input and configured to impress an input voltage across the primary winding. The power converter further includes a hybridge synchronous rectifier coupled to the secondary winding and including first and second synchronous rectifier switches. The power converter still further includes a separate drive winding wound on the power transformer and coupled between the first and second synchronous rectifier switches. The separate drive winding is configured to alternately energize the first and second synchronous rectifier switches.

Self-synchronized drive circuit for a synchronous rectifier in a

For use with a power supply including first and second parallel-coupled converters having interleaved first and second switches, respectively, the first and second switches limited to a duty cycle of less than about 50 percent, a current mode control circuit and a method of current-mode controlling the power supply. In one embodiment, the current mode control circuit, includes: (1) an interconverter current transformer, coupled to an input of the power supply, that senses an input current of the power supply and (2) a controller, coupled to the current transformer, that moderates the duty cycle of the first and second switches as a function of the input current to cause the first and second converters to share an output current of the power supply.

Current mode control circuit for paralleled power supply and method of

A method of mounting a power semiconductor die on a substrate, a package for the die and a power supply including the package. The die has a first power terminal on a first surface thereof and a second power terminal on an opposing second surface thereof. The method including the steps of: (1) forming an electrically-conductive, mechanical bond between the first surface and a first location on the substrate, the mechanical bond electrically coupling the first power terminal to the substrate and (2) soldering an elongated electrically conductive strap to the second surface and a second location on the substrate, the conductive strap composed of a material having an electrical resistivity at most about 5.0.times.10-.sup.8 ohm-meters (.OMEGA.-m) and forming a low impedance path between the second power terminal and the second location.

Package for a power semiconductor die and power supply employing the same

A magnetic device, a method of manufacturing the magnetic device and a DC/DC converter employing the magnetic device. The magnetic device comprises: (1) a first core-portion composed of a magnetic material and having first and second legs associated therewith, the first leg having a first end face and a predetermined first cross-sectional area, the second leg having a second end face and a predetermined second cross-sectional area different from the first cross-sectional area, (2) a winding assembly having first and second windings associated therewith and disposed about first and second winding apertures, respectively, the first and second legs passing through the first and second winding apertures, respectively, to couple the first and second windings magnetically to the first and second legs, respectively, (3) a second core-portion composed of the magnetic material and adapted to mate with the first and second legs of the first core-portion and (4) an interstitial non-magnetic material of a predetermined uniform thickness disposed on the first and second end faces and joining the first and second core-portions to form a core for the magnetic device, the non-magnetic material forming a uniform air gap in the first and second legs.

Magnetic core structures and construction techniques therefor

A power converter with a self synchronized synchronous rectifier includes one or two drive windings to provide positive drive to the control electrodes of the controlled switches (FETs) of a self synchronized synchronous rectifier. The polarities of these windings are selected so that the switched devices are driven appropriately to rectify the periodic signal output of the secondary winding of the power transformer of the converter. In some arrangements one or two drive windings are included as extra windings in the power transformer and connected to provide the proper polarity drive signals. The turn ratios of the drive windings to the other windings are selected to provide the proper gate drive signal levels. In an alternative arrangement a separate drive transformer may be provided to supply the gate drive signals.

Growing community of inventors

Allen, TX, United States of America

Wayne C Bowman