Hong Kong Applied Science and Technology Research Institute Company, Limited

Ziyang Gao

Kun Wu

Danting Xu

Chang Hwa Chung

Xiang Chen

Man Lung Sham

Man-Lung Sham

Tak Lok Shum

Shi Wo Chow

Tung Ching Lui

Xiaoyong Hu

Ya Lv

Man Lung Ivan Sham

Xunqing Shi

Yat Kit Tsui

Chi Kuen Vincent Leung

Lap Wai Lydia Leung

Ngok Man Sze

Lourdito M Olleres

Yuxing Ren

Shek Mong Wong

Chang Hwa Tom Chung

Chit Sang Chan

Kwan Wai Raymond To

Lap-Wai Lydia Leung

Minglu Xia

Zhou Li

Wei Qian

A level shifter circuit uses standard n-channel and p-channel transistors except for a pair of Lateral-Diffusion Metal-Oxide-Semiconductor (LDMOS) transistors that have an added lateral diffusion under the gate between the source and the conduction channel, increasing the breakdown voltage. The source of each LDMOS transistor connects to a drain of a transient differential transistor that has its gate driven by a oneshot that generates a pulse after an input transition. After the pulse ends a holding differential transistor draws a smaller bias current from the LDMOS transistors. The source of each LDMOS transistor connects to the drain and gate of a p-channel sensing transistor that drives gates of mirror transistors generating mirrored currents to cross-coupled n-channel mirror transistors that drive both terminals of a bistable latch that holds the output using a floating ground between driver transistors of a Buck converter switched by the bistable latch.

High-speed level-shifter for power-conversion applications

A power-converter module has a switching Printed Circuit Board (PCB) with power transistors that generate heat. Ground, an input power supply, and an output power supply to the power transistors connect through metal traces on the switching PCB directly to interposer heat sinks that are soldered between the switching PCB and a system PCB. The metal traces and interposer heat sinks carry both supply or ground currents and heat away from the power transistors. These power and ground currents continue from the interposer heat sinks to the system PCB through direct solder joints between the system PCB and the interposer heat sinks. An interposer PCB has a same thickness as the interposer heat sinks and carries control signals from the system PCB to the switching PCB, bypassing the interposer heat sinks. The interposer heat sinks have an interposer portion soldered between the PCBs and fins beyond the switching PCB footprint.

Power converter package with thermally enhanced interposers to cooling fins

An active filter reduces Electro-Magnetic Interference (EMI) created by current flowing through a power line. The active filter connects to the power line at a single node through a connection capacitor. A sense current flows through the connection capacitor when the power line current changes. This sense current is applied to a gain control circuit having cross-coupled PNP transistors that drive currents to both terminals of a variable capacitor. The variable capacitor converts these currents to a voltage that is injected back into the power line through the connection capacitor as an injected compensation voltage that compensates for the sensed current.

Active filter for electromagnetic interference (EMI) reduction using a single connection point and a negative impedance converter with cross-coupled transistors

A wireless power transmitter has electromagnets and a transmitter coil mounted on a moving plate. Current in the main DC circuit is switched into the electromagnets by transistors that control the amount and direction of current through the electromagnets to control the strength and polarity of electromagnetic fields generated by the electromagnets. A controller initially drives a high gate voltage onto transistors to cause the electromagnets on the transmitter to generate a maximum attractive force with magnets on the receiver, causing the moving plate to move the transmitter coil into closer alignment with the receiver coil. A power factor is measured on both receiver and transmitter to estimate the power transfer efficiency. The controller then reduces the gate voltage by a step size and the power factors are measured again. The gate voltage continues to be adjusted to optimize the power transfer efficiency until reaching a maxima.

Self-aligning wireless power transfer system that switches power current into aligning electromagnets

An active filter reduces Electro-Magnetic Interference (EMI) created by current flowing through a power line. The active filter connects to the power line at a single node through a connection capacitor. A sense current flows through the connection capacitor when the power line current changes. This sense current is applied to a non-inverting input of an op amp to drive a power amplifier circuit through a filter capacitor. The power amplifier circuit increases the current drive of the op amp to charge a transfer capacitor that converts the power amplifier output current to a transfer voltage. The transfer capacitor is connected to the connection capacitor so that the transfer voltage is injected back into the power line through the connection capacitor as an injected voltage that compensates for the sensed current. Op amp gain is adjustable by variable resistors that connect to the inverting input of the op amp.

Active filter for electromagnetic interference (EMI) reduction using a single connection point and a negative impedance converter

An assembly for power converting includes a circuit board, a power switching circuit mounted on the circuit board, an inductor coil that includes a winding and two ends, a magnetic core that is surrounded by the winding of the inductor coil, and a magnetic mixture that encapsulates the circuit board, the power switching circuit, the inductor coil and the magnetic core. The winding of the inductor coil is stacked above the power switching circuit and is sufficiently large to fill up a size of the assembly.

Power converter

A power device package includes a substrate, a high side power device, a low side power device and a driver device. The substrate includes a top surface, a bottom surface and a plurality of vias that extend through the substrate. The high side and low side power devices are disposed on the top surface of the substrate and connected with each other. The driver device is disposed on the bottom surface of the substrate and electrically connected with the high side and low side power devices through the vias to drive the high side and low side power devices in response to a control signal. The distance between the driver device and the high side and low side power devices is determined by the thickness of the substrate such that that a parasitic inductance between the driver device and the high side power device or the low side power device is reduced.

Power device package

Example embodiment is a power converter that adopt a 3D structure to increase the power density and improve thermal performance. The power converter includes a bottom substrate and at least one side substrate. Both the bottom substrate and the side substrate are rigid. Each side substrate is connected with the bottom substrate by a flexible substrate and forms an angle with the bottom substrate. The bottom substrate is further electrically connected with a plurality of surface mounting devices which are rigid. The flexible substrate provides electrical connection between the bottom substrate and the side substrate.

Two or more power converters are connected in parallel to supply power current to a joining node through connecting resistors. An output voltage before the connecting resistor in each power converter is sampled and divided by a sampling ratio to generate sampled voltages for each power converter. A current sharing circuit for each power converter receives the local sampled voltage and another sampled voltage from another power converter. The current sharing circuit generates an adjustment voltage that is injected into a feedback loop. The adjustment voltage modifies the output voltage of the power converter, adjusting and balancing the power current delivered by that power converter. Power currents from several power converters are reduced and balanced when the same sampling ratio is used for all power converters. Current hogging by one power converter is prevented.

Current-sharing circuit for DC-DC converters

A power electronic package includes a first substrate, a second substrate oppositely disposed from the first substrate, one or more chips disposed between the substrates, and at least three spacers. The spacers control a height variation of the power electronic package and protect the chips and other electronics from experiencing excessive stress. The height of the spacers is determined based on a height of the chips, on a height of solder blocks that connect the chips to the top substrate, and on a height of solder blocks that connect the chips to the bottom substrate.

Three dimensional fully molded power electronics module having a plurality of spacers for high power applications

The present invention discloses a fluid cooling assembly which facilitates turbulent flow inside the assembly so as to achieve better heat dissipating effect. The cooling assembly comprises an enclosed chamber with an inlet and an outlet for fluid to pass through; together with a heat spreader; a plurality of micropillars and a plurality of heat dissipating fins installed inside the assembly. When fluid flows through the chamber, these elements in combination are adapted to create an enhanced turbulent flow upon the fluid so as to effectively dissipate heat from said heat spreader through the fluid.

Locally enhanced direct liquid cooling system for high power applications

A system for bonding a die to a high power dielectric carrier such as a ceramic dielectric core with double-sided conductive layers is described. In the system, the upper conductive layer has a first area whose surface has a first wettability. A second area that at least partially surrounds the first area has a surface with a second wettability that is greater than the first wettability. During bonding, an adhesive material bonding a chip to the substrate spreads among the first area by a downward force placed on the chip. Due to the difference in wettability, the adhesive material then spreads among the second area by a wetting force generated by the greater second wettability of the second area surface causing the chip to be drawn down until reaching a predetermined position. The predetermined position can be determined by substrate protrusions or substrate cavities.

High power dielectric carrier with accurate die attach layer

A tire pressure monitoring sensor moveable inside a tire includes a housing holding a pressure sensing/transmitting unit, one or more batteries and an antenna for transmitting a signal indicating interior tire pressure. In one embodiment, the components are assembled within the housing such that the center of gravity is along a housing geometric center. During tire rotation, the monitor independently rotates within the tire and is particularly useful for slow-rotating tires, such as those used in gantry systems. Alternatively, the pressure monitoring sensor components are assembled within the housing such that the center of gravity is offset from a housing geometric center. Centripetal force generated during tire rotation causes the monitor to rotate with the tire itself and is useful for faster-rotating tires, such as motor vehicle tires. A tire pressure monitoring system includes the monitor and a receiver positioned outside the tire for receiving the monitoring signals.

Mount-free tire pressure monitoring system

A self-powered impulse detecting system comprising a signal transmitter; an energy storage component; and an energy harvester comprising a top plate configured to receive a stress impulse by an external object on its top surface; a bottom plate positioned opposite to the top plate and leaving room in between the bottom plate and the top plate; an elastic element positioned in between the top plate and the bottom plate; a bendable substrate attached at a first end to the bottom surface of the top plate, the bendable substrate is configured to bend freely, colliding with the top plate and a stopper; a piezoelectric element positioned on the bendable substrate; a deadweight attached to a second end of the bendable substrate; wherein collisions between the bendable substrate, the top plate and the stopper cause the bendable substrate to bend along with the piezoelectric element to generate power.

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Hong Kong, China

Ziyang Gao