Future Wei Technologies, Inc.

Huawei Technologies Co., Limited

Bing Cai

Dianbo Fu

Hengchun Mao

Heping Dai

Xujun Liu

Liming Ye

Daoshen Chen

Zhihua Liu

Ce Liu

Pedro Angel Fernandez

Yuyu Qiao

Zhaozheng Hou

A dual voltage power system for selectively providing direct current (DC) at two different voltages. The system includes a plurality of universal rectifiers each of which may be configured to operate under a plurality of operating modes using a plurality of switches which may be controlled by a power shelf controller.

Flexible rectifier for providing a variety of on-demand voltages

An embodiment holdup time circuit of a bridgeless power factor correction circuit comprises a charge device connected between an output terminal of a bridgeless power factor correction circuit and an energy storage apparatus, a discharge device connected between the energy storage apparatus and an input of the bridgeless power factor correction circuit, the energy storage apparatus and the bridgeless power factor correction circuit comprising a first boost converter, a second boost converter, a first switch and a second switch, wherein the first switch is connected between the first boost converter and ground and the second switch is connected between the second boost converter and ground.

Holdup time circuit and method for bridgeless PFC converter

A system comprises an input power stage coupled to a primary side of a transformer, an output power stage coupled to a secondary side of a transformer, a first common node capacitor and a common node resistor connected in series between a midpoint of the secondary side of the transformer and ground and a detector having an input connected to a common node of the first common node capacitor and the common node resistor, and an output connected to a control circuit, wherein the control circuit is configured to dynamically adjust a switching frequency of the system based upon an output of the detector.

Apparatus and efficiency point tracking method for high efficiency resonant converters

A method comprises connecting a first resonant converter and a second resonant converter in parallel, detecting a first signal indicating a first soft switching process of the first resonant converter and a second signal indicating a second soft switching process of the second resonant converter and adjusting a first switching frequency of the first resonant converter by a first control circuit and a second switching frequency of the second resonant converter by a second control circuit until a load current flowing through the first resonant converter is substantially equal to a load current flowing through the second resonant converter.

A method for improving a power converter's efficiency comprises detecting an input voltage of a power converter, determining an operation mode of the power converter based upon the input voltage of the power converter and generating a plurality of gate drive signals based upon a damped gain control, wherein the damped gain control is configured such that an output voltage of the power converter is in a range from a tightly regulated output voltage to an unregulated output voltage.

Apparatus and method for loosely regulated power converters

An apparatus comprising a first rectifier, wherein an output of the first rectifier is coupled to a first terminal, a second rectifier, wherein an output of the second rectifier is coupled to a second terminal, a first electronic switch configured to selectively route an alternating current (AC) signal to the first rectifier or the second rectifier, an inverter configured to operate in the event that the first electronic switch does not receive the AC signal to receive a direct current (DC) signal, and convert the DC signal to a second AC signal, a second electronic switch configured to selectively route the DC signal from the first terminal or the second terminal to the inverter, and a third electronic switch configured to selectively route the second AC signal to the first rectifier or the second rectifier.

An embodiment power converter package comprises a semiconductor die, an output inductor, a plurality of input capacitors and output capacitors. The semiconductor die, the output inductor and the plurality of capacitors are mounted on a lead frame and connected one to another through various pads on the lead frame. The semiconductor die comprises a high side switch, a low side switch and a driver. The power converter package is electrically coupled to an external pulse width modulation controller through a variety of input and output pads.

Power converter package structure and method

A power system comprising a non-isolated voltage regulator configured to couple to an input voltage and produce an output voltage, wherein the non-isolated voltage regulator is in a power distribution system and configured to boost the input voltage when the input voltage is less than a minimum output voltage, to reduce the input voltage when the input voltage is greater than a maximum output voltage, and to pass-through the input voltage when the input voltage is greater than or equal to the minimum output voltage and less than or equal to the maximum output voltage.

High efficiency high power density power architecture based on buck-boost regulators with a pass-through band

An embodiment holdup time circuit of a bridgeless power factor correction circuit comprises a charge device, an energy storage apparatus and a discharge device. The charge device comprises a first terminal coupled to a bridgeless power factor correction circuit and a second terminal coupled to the energy storage apparatus. The discharge device comprises a first terminal coupled to the energy storage apparatus and a second terminal coupled to the bridgeless power factor correction circuit.

A converter comprises an input stage coupled to a power source, wherein the input stage comprises a plurality of power switches, a resonant tank coupled to the plurality of power switches, a transformer coupled to the resonant tank, an output stage coupled to the transformer, an efficiency point tracking indicator coupled to the converter, a detector coupled to the efficiency point tracking indicator and a control circuit configured to receive an efficiency point tracking signal from the detector and adjust a switching frequency of the power switches based upon the efficiency point tracking signal.

An embodiment hybrid dc/dc converter comprises a first power source and a low power converter coupled to the first power source. The low power converter generates an output connected in series with the first power source. The hybrid dc/dc converter further comprises a selection network coupled to the first power source and the output of the low power converter and a main unregulated power converter coupled to the selection network. By controlling the voltage across the output of the low power converter, the hybrid dc/dc converter can achieve high efficiency through the unregulated power converter.

Hybrid DC/DC converters and methods

An embodiment common mode noise reduction apparatus comprises a common mode choke, a balance inductor, a first capacitor and a second capacitor. The common mode choke is placed between an input dc source and a primary side network of an isolated power converter. The balance inductor is coupled between an upper terminal of a primary winding of the isolated power converter and a negative terminal of the input dc source. The first capacitor is coupled between the upper terminal of a primary side of a transformer and an upper terminal of a secondary side of the transformer of the isolated power converter. The second capacitor is coupled between a lower terminal of the primary side of the transformer and a lower terminal of the secondary side of the transformer of the isolated power converter.

Common mode noise reduction apparatus and method

A soft switching apparatus comprises an energy recovery channel formed by two diodes in series connection and a resonant tank formed by an inductor and a capacitor. The soft switching apparatus is coupled to the primary side of a bridge converter. An energy transfer process during L-C resonance helps to reduce the amplitude of the current flowing through the inductor in a freewheeling period. Furthermore, the soft switching apparatus can help to reduce the voltage stress across the secondary switching devices as well as the shoot-through currents flowing through the secondary switching devices, and thus enabling the reduction or elimination of dead time in a secondary synchronous rectifier control scheme.

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Richardson, TX, United States of America

Bing Cai