Abstract: A spliced screen and a display terminal are disclosed. In the spliced screen, a structural component is disposed on two adjacent display panels and covers a splicing gap between the two adjacent display panels. A lamp plate is disposed on a surface of the structural component. When the spliced screen displays an image, a plurality of luminescent bodies disposed on the lamp plate close to the display panels also emit light, thereby preventing black strips from appearing on the image. In the spliced screen, a viewing angle of the display panels and a viewing angle of the lamp plate are same, so that a brightness of the display panels and a brightness of the lamp plates are same when the spliced screen is viewed from a lateral side. As such, display quality is improved.

Abstract: According to an embodiment of the present disclosure, a display screen, a display device, and a method for manufacturing the display screen are disclosed. The display screen includes a display panel and a light bar. The light bar includes an array substrate and a plurality of light emitting elements, and a first gap is provided between two adjacent light emitting elements. A light absorbing layer is arranged in the first gap between at least two adjacent light emitting elements. By arranging the light absorbing layer, the side light of the light emitting elements can be partially absorbed, thereby reducing an emission angle of the light bar.

Abstract: Embedded die packaging for high voltage, high temperature operation of power semiconductor switching devices is disclosed, wherein a power semiconductor die is embedded in laminated body comprising a layer stack of a plurality of dielectric layers and electrically conductive layers, and wherein a first thermal pad on one side of the package and a second thermal pad on an opposite side of the package provides for dual-side cooling. Example embodiments of the dual-side cooled package may be based on a bottom-side cooled layup with a primary bottom-side thermal pad and a secondary top-side thermal pad, or a top-side cooled layup with primary top-side thermal pad and a secondary bottom side thermal pad, using layups with or without a leadframe. For example, the power semiconductor switching device comprises a GaN power transistor, such as a GaN HEMT rated for operation at ?100V or ?600V, for switching tens or hundreds of Amps.

Abstract: A multi-zone substrate for a power stage assembly comprising at least one bottom-cooled semiconductor power switching device and driver components, for integration on a common substrate. A first zone provides electrical connections and a thermal pad for mounting at least one bottom-cooled semiconductor switching device, the first zone comprising dielectric and conductive layers which provide a power substrate optimized for thermal performance. A second zone provides electrical connections for mounting driver components, the second zone comprising dielectric and conductive layers providing a driver substrate optimized for electrical performance. For example, the first zone comprises a single layer metal interconnect structure with a first thermal resistance, the second zone comprises a multi-layer metal interconnect structure with a second thermal resistance, the first thermal resistance being less than the second thermal resistance.

Abstract: Low inductance power modules for ultra-fast wide-bandgap semiconductor power switching devices are disclosed. Conductive tracks define power buses for a switching topology, e.g. comprising GaN E-HEMTs, with power terminals extending from the power buses through the housing to provide a heatsink-to-busbar distance which meets creepage and clearance requirements. Low-profile, low-inductance terminals for gate and source-sense connections extend from contact areas located adjacent each power switching device to provide for a low inductance gate drive loop, for high di/dt switching. The gate driver board is mounted on the low-profile terminals, inside or outside of the housing, with decoupling capacitors provided on the driver board. For paralleled switches, additional terminals, which are referred to as dynamic performance pins, are provided to the power buses.

Abstract: An active gate voltage control circuit for a gate driver of a power semiconductor switching device comprising a power semiconductor transistor, such as a GaN HEMT, provides active gate voltage control comprising current burst mode operation and protection mode operation. The gate-source turn-on voltage Vgs(on) is increased in burst mode operation, to allow for a temporary increase of saturation current. In protection mode operation, a multi-stage turn-off may be implemented, comprising reducing Vgs(on) to implement fast soft turn-off, followed by full turn-off to bring Vgs(on) below threshold voltage, to reduce switching transients such as Vds spikes. Circuits of example embodiments provide for burst mode operation for enhanced saturation current, to increase robustness of enhancement mode GaN power switching devices, e.g. under overcurrent and short circuit conditions, or to provide active gate voltage control which adjusts dynamically to specific operating conditions or events.

Abstract: Hybrid power switching stages and driver circuits are disclosed. An example semiconductor power switching device comprises a high-side switch and a low-side switch connected in a half-bridge configuration, wherein the high-side switch comprises a GaN power transistor and the low-side switch comprises a Si MOSFET. The Si—GaN hybrid switching stage provides enhanced performance, e.g. reduced switching losses, in a cost-effective solution which takes advantage of characteristics of power switching devices comprising both GaN power transistors and Si MOSFETs. Also disclosed is a gate driver for the Si—GaN hybrid switching stage, and a semiconductor power switching stage comprising the gate driver and a Si—GaN hybrid power switching device having a half-bridge or full-bridge switching topology.

Abstract: An active gate voltage control circuit for a gate driver of a power semiconductor switching device comprising a power semiconductor transistor, such as a GaN HEMT, provides active gate voltage control comprising current burst mode operation and protection mode operation. The gate-source turn-on voltage Vgs(on) is increased in burst mode operation, to allow for a temporary increase of saturation current. In protection mode operation, a multi-stage turn-off may be implemented, comprising reducing Vgs(on) to implement fast soft turn-off, followed by full turn-off to bring Vgs(on) below threshold voltage, to reduce switching transients such as Vds spikes. Circuits of example embodiments provide for burst mode operation for enhanced saturation current, to increase robustness of enhancement mode GaN power switching devices, e.g. under overcurrent and short circuit conditions, or to provide active gate voltage control which adjusts dynamically to specific operating conditions or events.

Abstract: Hybrid power switching stages and driver circuits are disclosed. An example semiconductor power switching device comprises a high-side switch and a low-side switch connected in a half-bridge configuration, wherein the high-side switch comprises a GaN power transistor and the low-side switch comprises a Si MOSFET. The Si—GaN hybrid switching stage provides enhanced performance, e.g. reduced switching losses, in a cost-effective solution which takes advantage of characteristics of power switching devices comprising both GaN power transistors and Si MOSFETs. Also disclosed is a gate driver for the Si—GaN hybrid switching stage, and a semiconductor power switching stage comprising the gate driver and a Si—GaN hybrid power switching device having a half-bridge or full-bridge switching topology.

Abstract: Low inductance power modules for ultra-fast wide-bandgap semiconductor power switching devices are disclosed. Conductive tracks define power buses for a switching topology, e.g. comprising GaN E-HEMTs, with power terminals extending from the power buses through the housing to provide a heatsink-to-busbar distance which meets creepage and clearance requirements. Low-profile, low-inductance terminals for gate and source-sense connections extend from contact areas located adjacent each power switching device to provide for a low inductance gate drive loop, for high di/dt switching. The gate driver board is mounted on the low-profile terminals, inside or outside of the housing, with decoupling capacitors provided on the driver board. For paralleled switches, additional terminals, which are referred to as dynamic performance pins, are provided to the power buses.

Abstract: Low inductance power modules for ultra-fast wide-bandgap semiconductor power switching devices are disclosed. Conductive tracks define power buses for a switching topology, e.g. comprising GaN E-HEMTs, with power terminals extending from the power buses through the housing to provide a heatsink-to-busbar distance which meets creepage and clearance requirements. Low-profile, low-inductance terminals for gate and source-sense connections extend from contact areas located adjacent each power switching device to provide for a low inductance gate drive loop, for high di/dt switching. The gate driver board is mounted on the low-profile terminals, inside or outside of the housing, with decoupling capacitors provided on the driver board. For paralleled switches, additional terminals, which are referred to as dynamic performance pins, are provided to the power buses.

Abstract: A 3-level T-type neutral point clamped (NPC) inverter/rectifier is disclosed in which neutral point clamping is dynamically enabled/disabled responsive to load, e.g. enabled at low load for operation in a first mode as a 3-level inverter/rectifier and disabled at high/peak load for operation in a second mode as a 2-level inverter/rectifier. When the neutral clamping leg is enabled only under low load and low current, middle switches S2 and S3 can be smaller, lower cost devices with a lower current rating. Si, SiC, GaN and hybrid implementations provide options to optimize efficiency for specific load ratios and applications. For reduced switching losses and enhanced performance of inverters based on Si-IGBT power switches, a hybrid implementation of the dual-mode T-type NPC inverter is proposed, wherein switches S1 and S4 comprise Si-IGBTs and switches S2 and S3 of the neutral clamping leg comprise GaN HEMTs. Applications include electric vehicle traction inverters.

Abstract: Low inductance power modules for ultra-fast wide-bandgap semiconductor power switching devices are disclosed. Conductive tracks define power buses for a switching topology, e.g. comprising GaN E-HEMTs, with power terminals extending from the power buses through the housing to provide a heatsink-to-busbar distance which meets creepage and clearance requirements. Low-profile, low-inductance terminals for gate and source-sense connections extend from contact areas located adjacent each power switching device to provide for a low inductance gate drive loop, for high di/dt switching. The gate driver board is mounted on the low-profile terminals, inside or outside of the housing, with decoupling capacitors provided on the driver board. For paralleled switches, additional terminals, which are referred to as dynamic performance pins, are provided to the power buses.

Abstract: A 3-level T-type neutral point clamped (NPC) inverter/rectifier is disclosed in which neutral point clamping is dynamically enabled/disabled responsive to load, e.g. enabled at low load for operation in a first mode as a 3-level inverter/rectifier and disabled at high/peak load for operation in a second mode as a 2-level inverter/rectifier. When the neutral clamping leg is enabled only under low load and low current, middle switches S2 and S3 can be smaller, lower cost devices with a lower current rating. Si, SiC, GaN and hybrid implementations provide options to optimize efficiency for specific load ratios and applications. For reduced switching losses and enhanced performance of inverters based on Si-IGBT power switches, a hybrid implementation of the dual-mode T-type NPC inverter is proposed, wherein switches S1 and S4 comprise Si-IGBTs and switches S2 and S3 of the neutral clamping leg comprise GaN HEMTs. Applications include electric vehicle traction inverters.

Abstract: An AC/DC conversion apparatus includes first, second, and third AC/DC conversion modules operated by a controller in two modes of operation. In the first mode, the input AC signal is 3-phase and each of the three modules are enabled to handle a respective one of the input phases. In the second mode, the input AC signal is single phase and the first and second modules are enabled to deliver output power based on the single-phase AC input, while the controller actuates an H-bridge switches in the third module to which active filter circuitry is connected, to reduce an AC component in the output signal. The active filter circuitry can be selectively connected to the H-bridge switches when single-phase operation is desired, which circuitry may be disposed in a filter housing having male electrical terminals that cooperate with corresponding female terminals associated with the third module.

Abstract: A single-phase AC/DC electric power conversion apparatus includes an indirect matrix converter having an input interface to receive a first alternating current (AC) signal and an output interface to produce a second AC signal, where the first AC signal has a grid frequency. A transformer has a primary winding and an electrically isolated and magnetically coupled secondary winding. A coupling inductor is connected in series between the output interface of the indirect matrix converter and the primary winding. An H-bridge switching arrangement is connected to the secondary winding and produces an output signal having a DC component and at least one AC component. The at least one AC component has a second order harmonic of the grid frequency. An active filter reduces the second order harmonic AC component. A modular conversion apparatus for three-phase power replicates the single-phase apparatus as a module for each phase and omits the active filter.

Abstract: A hybrid switch apparatus includes a gate drive circuit producing a gate drive signal, a GaN high electron mobility transistor (HEMT) having a first gate, a first drain, and a first source. A silicon (Si) MOSFET has a second gate, a second drain, and a second source. The GaN HEMT and the Si MOSFET are connected in a parallel arrangement so that (i) the first drain and the second drain are electrically connected and (ii) the first source and the second source are electrically connected. The second gate is connected to the gate drive circuit output to receive the gate drive signal. A delay block has an input connected to the gate drive circuit output and an delay block output is configured to produce a delayed gate drive signal for driving the GaN HEMT.

Abstract: An AC/DC conversion apparatus includes first, second, and third AC/DC conversion modules operated by a controller in two modes of operation. In the first mode, the input AC signal is 3-phase and each of the three modules are enabled to handle a respective one of the input phases. In the second mode, the input AC signal is single phase and the first and second modules are enabled to deliver output power based on the single-phase AC input, while the controller actuates an H-bridge switches in the third module to which active filter circuitry is connected, to reduce an AC component in the output signal. The active filter circuitry can be selectively connected to the H-bridge switches when single-phase operation is desired, which circuitry may be disposed in a filter housing having male electrical terminals that cooperate with corresponding female terminals associated with the third module.

Abstract: A single-phase AC/DC electric power conversion apparatus includes an indirect matrix converter having an input interface to receive a first alternating current (AC) signal and an output interface to produce a second AC signal, where the first AC signal has a grid frequency. A transformer has a primary winding and an electrically isolated and magnetically coupled secondary winding. A coupling inductor is connected in series between the output interface of the indirect matrix converter and the primary winding. An H-bridge switching arrangement is connected to the secondary winding and produces an output signal having a DC component and at least one AC component. The at least one AC component has a second order harmonic of the grid frequency. An active filter reduces the second order harmonic AC component. A modular conversion apparatus for three-phase power replicates the single-phase apparatus as a module for each phase and omits the active filter.

Abstract: A hybrid switch apparatus includes a gate drive circuit producing a gate drive signal, a GaN high electron mobility transistor (HEMT) having a first gate, a first drain, and a first source. A silicon (Si) MOSFET has a second gate, a second drain, and a second source. The GaN HEMT and the Si MOSFET are connected in a parallel arrangement so that (i) the first drain and the second drain are electrically connected and (ii) the first source and the second source are electrically connected. The second gate is connected to the gate drive circuit output to receive the gate drive signal. A delay block has an input connected to the gate drive circuit output and an delay block output is configured to produce a delayed gate drive signal for driving the GaN HEMT.