Lucent Technologies Inc.

At&t Bell Laboratories

At+t Corp.

Kenneth J Timm

Mark E Jacobs

Vijayan J Thottuvelil

Charles E Harm

Ashraf W Lotfi

Jeffrey John Boylan

Qing Chen

Anatoly Feygenson

Greg H Fasullo

Richard H Hock

A controller for a power switch having an isolated control terminal and coupled to a secondary winding of a drive transformer and a method of preventing spurious turn-on of the power switch. The controller includes: (1) a controllable switch, coupled between the secondary winding and the power switch, that alters a control voltage of the power switch in response to a characteristic of the secondary winding, and (2) a bias circuit coupled to the controllable switch and the power switch that provides a voltage differential between the controllable switch and the power switch to prevent spurious turn-on thereof.

Controller for a power switch and method of operation thereof

A programmable controller for switch-mode power converters that operates in a digital domain without reliance on operation software and the ability to vastly reduce or eliminate analog circuitry. The digital controller is re-programmable. In one embodiment, the substantially digital portion of the controller is a Field Programmable Gate Array that controls operation of the converter by generally converting an analog reference signal(s) (e.g. the voltage output) into the digital domain. The controller then can perform distributed arithmetic to generate a square wave signal capable of controlling at least a main switch of the converter. The present invention can, if desired, essentially eliminate analog controllers in power conversion systems such as switch-mode converters.

Programmable digital controller for switch mode power conversion and

For use in a distributed power system having first and second power processing modules, a power processing module for, and method of synchronizing an operation of the second power processing module with the first power processing module and a power converter employing the power processing module or the method. In one embodiment, the power processing module includes: (1) a synchronization input terminal adapted to receive a first control signal, (2) a free-running oscillator that generates a gate drive signal for controlling a switch of the power processing module, the gate drive signal having a frequency that is a free-running frequency of the power processing module, (3) a synchronization circuit, coupled to the synchronization input terminal and the free-running oscillator, that synchronizes the gate drive signal with the first control signal and (4) a frequency setting circuit, coupled to the synchronization input terminal and the free-running oscillator, that modifies an operation of the free-running oscillator.

System and method for synchronizing and interleaving power modules

A rectifier for a switching power supply or the like. The recitifier has a plurality of diodes coupled in parallel, each diode having in series therewith a saturable inductor and a node disposed between the diode and the inductor to form a diode/inductor pair. At least one resistor is connected between at least two of the nodes to assure nearly equal current flow in the diodes. Alternatively, a link winding on at least two of the inductors are coupled together to achieve current balancing.

Current balancing arrangement for paralleled diode arrangements

A high performance isolated gate drive circuit for driving MOSFET is disclosed which uses a MOSFET pull-down device, provides unusually low gate discharge impedance, exceptionally fast turn-off of the controlled switch and reduced power dissipation in the overall gate drive circuit. It also provides superior off-time noise immunity.

High performance drive structure for MOSFET power switches

An isolated MOSFET gate drive includes circuitry to provide a negative gate bias during the off time of the MOSFET to enhance its immunity to inadvertent turn-on. The bias is generated by a self contained two terminal passive network which may be 'floated' at any potential with respect to ground. This bias is automatically generated through the action of the network to the gate drive waveform, eliminating the need for an external bias supply to provide this voltage. The bias supply is located locally, thus eliminating the need for long interconnects which may interfere with circuit operation. The bias network in one implementation is a combination of a capacitor and non-linear semiconductor device with a fixed voltage breakdown characteristic. This two-component implementation maintains the capability of producing systems with high packaging densities.

Apparatus and method for generting negative bias for isolated MOSFET

A battery charger control includes a thermal sensor attached to the battery being charged. If the temperature readings indicate a thermal runaway condition the charging current output is adjusted in accord with the temperature reading by means of voltage injeciton into an output sense lead of the charging circuitry as a means of achieving a control that prevents thermal runaway of the battery while still permitting continuous charging of the battery.

Battery charger with thermal runaway protection

Frequency variation in a resonant zero voltage switching (ZVS) power converter is combined with supplemental duty cycle modulation to obtain voltage regulation and to narrow the required frequency band needed for regulation of a given output load. These two regulation processes are applied simultaneously to the power switch control in order to accommodate a wider range of regulated load. Hence in the alternative, for a given load range a smaller frequency range is needed than would be the case if frequency variation alone is used. The regulation control circuit includes both a duty cycle modulator and a frequency modulator each being responsive to an error signal responsive to a differential between an output voltage of the converter and a reference voltage. Each individual modulator has its own transfer function; one transfer function being kHz/volt the other transfer function being % duty cycle/volt. The regulation control circuit output is a rectangular pulse type signal that contains both elements of frequency modulation and duty cycle modulation.

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Rockwall, TX, United States of America

Kenneth J Timm