Lucent Technologies Inc.

Other

At+t Corp.

At&t Bell Laboratories

Tyco Electronics Logistics Ag

Chiaro Networks Ltd

Allen Frank Rozman

Mark E Jacobs

Jeffrey John Boylan

Wayne C Bowman

Tony M Brewer

Ashraf W Lotfi

Vijayan J Thottuvelil

William Lonzo Woods, Jr

Simon Fraidlin

Jian Tan

Thomas C McDermott, Iii

Stephen F Newton

David Leonard Stevens

Thang Danh Truong

Van A Niemela

Richard H Hock

Randy T Heinrich

Thomas P Loftus, Jr

Wei Tang

Jeffrey L Boylan

Thomas Patrick Loftus, Jr, Deceased

By Marvin Thomas, Executor

Christopher P Davies

A repetitive burst-mode input signal that has a dark time portion, a preamble portion, and a payload portion is converted into a limited output signal in accordance with a decision threshold level, which is controlled by selectively coupling an averaged value of the burst-mode data amplitude to the decision threshold level. The timing sequence for selectively coupling the averaged signal value is controlled such that the average value of the burst-mode signal acquired during the preamble portion of the burst-mode signal is applied to the decision threshold level during substantially all of the payload portion. The control circuit may incorporate a phase-locked loop, which locks onto the repetitive dark time frequency and in response synthesizes a switchable track enable signal that controls the timing sequence of the decision threshold level. The phase-locked loop can employ all-digital, analog, and/or hybrid digital/analog circuitry.

Fast decision threshold controller for burst-mode receiver

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 system and method for improving response of a control loop of a power supply. The power supply is configured to drive a load having at least one characteristic associated therewith. In one embodiment, the system includes: (1) a sensing circuit, associated with the power supply, configured to sense the characteristic; and (2) a compensation circuit, coupled to the sensing circuit, configured to adaptively adjust the control loop based on the characteristic to improve the response.

System and method for improving control loop response of a power supply

An impedance network for passive shoot-through protection of active switches in clamp-mode topologies. In one exemplary embodiment a switch-mode converter, includes: a primary switch; an auxiliary switch coupled in series with a capacitor; and an impedance network, coupled to the primary switch and the auxiliary switch; configured to limit current during simultaneous conduction of the primary and auxiliary switches. The impedance network includes a resistor coupled in series to a diode and both in parallel with an inductor. The impedance network permits the design of a clamp-mode converter without the need for a delay between switch turn-off and turn-on of primary and auxiliary switches.

Protection circuit for active switches in clamp-mode topologies, and power converter employing the same

For use with a synchronous rectifier coupled to a secondary winding of a transformer and having a rectifier switch, a circuit for, and method of driving the rectifier switch and a power converter employing the circuit or the method. In one aspect of the present invention wherein the synchronous rectifier has at least first and second rectifier switches, the circuit includes: (1) a series-coupled drive winding and capacitor, coupled between a first control terminal of the first rectifier switch and a second control terminal of the second rectifier switch, that generates first and second drive signals and delivers the first and second drive signals to the first and second control terminals, respectively, and (2) first and second clamps, coupled to the first and second control terminals, respectively, that control first and second capacitive charges within the first and second rectifier switches to limit voltage excursions of the first and second drive signals.

Drive compensation circuit for synchronous rectifier and method of operating the same

A system and method for determining an output current of a power converter having an output capacitor and a component coupled thereto. In one embodiment, the system includes (1) an observer circuit, parallel-coupled to the output capacitor, that senses a voltage across the output capacitor and develops therefrom a capacitor signal representing a current through the output capacitor, (2) a sensor circuit, coupled to the component, that senses a characteristic of the component and develops therefrom a component signal representing a current through the component and (3) a summer circuit, coupled to the observer and sensor circuits, that derives an output signal representing the output current from the capacitor signal and the component signal.

System and method for determining output current and converter employing the same

An integrated circuit including a metal-semiconductor field-effect transistor (MESFET) having a nominal intrinsic capacitance and requiring a negative voltage to bias the MESFET into a non-conduction state, a method of driving the MESFET and a power converter employing the integrated circuit and method. In one embodiment, the integrated circuit includes a driver including a bias capacitor integrated with the MESFET. The driver is configured to apply a positive voltage to bias the MESFET into a conduction state, and apply the negative voltage to bias the MESFET into the non-conduction state without employing an external negative bias source.

Integrated circuit including a driver for a metal-semiconductor field-effect transistor

For use in a power system having a power train, a rectifier having an input and an output and a method of controlling the rectifier. The rectifier comprises: (1) switching circuitry coupled between the input and the output, the switching, circuitry adapted to operate in selected one of (a) a bidirectional mode of operation and (b) an unidirectional mode of operation to rectify substantially alternating current at the input to produce substantially direct current at the output; and (2) control circuitry coupled to a control input of the switching circuitry, the control circuitry capable of sensing a characteristic of the power system and transitioning the switching circuitry between the bidirectional mode and the unidirectional mode as a function of the characteristic thereby to prevent substantial reverse power flow through the rectifier.

Circuit and method for controlling a synchronous rectifier converter

A surface mountable power supply and a method of manufacturing the power supply. In one embodiment, the power supply includes: (1) a substrate having opposing upper and lower conductive layers (2) a lower electrical component having a first lead mounted on a first pad on the lower conductive layer and subject to forces capable of detaching the lower electrical component from the substrate when the power supply passes through a reflow soldering process, (3) an upper electrical component having a second lead mounted on a second pad on the upper conductive layer, (4) a solder located proximate the first lead, the lower electrical component of a sufficiently low weight such that a surface tension of a liquid state of the solder is sufficient to maintain the lower electrical component in contact with the lower conductive layer as the power supply passes through the reflow soldering process, (5) a planar magnetic device mounted on the substrate, the planar magnetic device having windings formed from a portion of conductive traces on the upper and lower conductive layers and a core disposed through apertures of the substrate and proximate the windings and (6) an inter-substrate conductive mount, coupled to the lower conductive layer, composed of a material having a melting point above a solder reflow temperature and adapted to mount the power supply to an adjacent substrate and provide a conductive path therebetween, the conductive mount including first and second compliant solder joints at interfaces of the substrate and the adjacent substrate, respectively.

Method of manufacturing a surface mountable power supply module

A DC--DC converter includes a transformer having a primary winding and a secondary winding. The secondary winding includes first and second terminals. An input circuit is connected to the primary winding for coupling an input DC voltage to the primary winding. A first output channel is coupled to the first terminal of the secondary winding, and is connected to a first output. The first channel includes a first diode connected in series with a first inductor. A second output channel is coupled to the first terminal of the secondary winding, and is connected to a second output. The second channel includes a second diode connected in series with a second inductor. A first and a second capacitor connect the first and second outputs to the second terminal of the secondary winding. A third diode connects the first output channel to the second terminal of the secondary winding. A fourth diode connects the second output channel to the second terminal of the secondary winding. An amplifier is coupled to one of the outputs. An integrator circuit is connected to the output terminal of the amplifier. A switch having an on and off time is connected to the transformer secondary winding and to the integrator circuit, such that the switch on and off time is controlled by the output of the integrator circuit. A fifth diode is coupled between the transformer secondary winding and the integrator circuit for resetting the integrator circuit.

Multiple output converter having self-synchronized pulse width

A DC--DC converter includes a transformer having at least a primary winding, a secondary winding and a drive winding. An input circuit is coupled to the transformer primary winding for coupling an input DC voltage to the transformer primary winding. A first output channel couples the transformer secondary winding to a first output. The first output channel includes a self-driven synchronous rectifier circuit, a first inductor, and a first capacitor. A first pulse width modulator is coupled between the first output channel and the input circuit to drive the input circuit, thereby regulating the first output channel. A second output channel couples the transformer secondary winding to a second output. The second output channel includes a control switch, a freewheeling rectifier, a second inductor, and a second capacitor. A second pulse width modulator is coupled between the second output channel and the control switch for controlling a conduction interval of the control switch, to thereby regulate the second output channel independent of the first output channel. An enabling switch, controlled by the second pulse width modulator, is coupled between the transformer drive winding and a control terminal of the control switch, such that the enabling switch modifies a voltage of the transformer drive winding to control the conductivity state of the control switch. A drive rectifier is coupled between the transformer drive winding and a control terminal of the freewheeling rectifier. A discharge switch is coupled to the control terminal of the freewheeling rectifier, wherein the discharge switch is controlled by the second pulse width modulator to control the conductivity state of the freewheeling rectifier.

Multiple output converter having secondary regulator using self-driven

Drive compensation circuit for synchronous rectifier and method of

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

A DC--DC converter includes a transformer having a primary winding and a secondary winding. The secondary winding includes first and second terminals. An input circuit is connected to the primary winding for coupling an input DC voltage to the primary winding. A first output channel is connected to the first terminal of the secondary winding, and is connected to a first output. The first channel includes a first switch connected in series with a first inductor. A second output channel is connected to the second terminal of the secondary winding, and is connected to a second output. A first and a second capacitor connect the first and second outputs to a return lead. A second switch connects the first output channel to the return lead. A third switch connects the second output channel to the return lead. A pulse width modulator is connected between one of the outputs to drive the input circuit. A pulse width modulator is connected between the first output and the first switch for regulating the duty ratio of the first output channel independently of the second output channel.

Multiple output converter having a single transformer winding and

For use in a power system having a power train, a rectifier having an input and an output and a method of controlling the rectifier. The rectifier comprises: (1) switching circuitry coupled between the input and the output, the switching circuitry adapted to operate in selected one of (a) a bidirectional mode of operation and (b) an unidirectional mode of operation to rectify substantially alternating current at the input to produce substantially direct current at the output; and (2) control circuitry coupled to a control input of the switching circuitry, the control circuitry capable of sensing a characteristic of the power system and transitions the switching circuitry between the bidirectional mode and the unidirectional mode as a function of the characteristic thereby to prevent substantial reverse power flow through the rectifier.

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Richardson, TX, United States of America

Allen Frank Rozman