Although standard internal combustion engine-driven vehicles can relatively easily obtain the electrical requirements of on-board systems from 12V battery-powered and corresponding 12V/14V alternators, they require higher power levels because of the several systems used in hybrid electric vehicles. For light-mixed, fully-mixed, plug-in hybrid or pure electric vehicles, the most energy-intensive component is the motor drive. The device needs to effectively drive the vehicle to travel at least for a certain period of time without the support of the internal combustion engine. In order to supply high-power motors of tens of kilowatts to hundreds of kilowatts without losing most of the electrical energy on the resistive connection channel, high current paths require higher voltages (range 600V to 1200V). But even at such high voltages, the required current level is only a few hundred amperes.
The introduction of high-voltage power grids has led the automotive industry to adopt two new power-intensive products: DC-AC inverters that convert DC into AC to drive motors, and DCs that exchange power between high-voltage grids and 12V grids. DC converter. Hybrid vehicles still need a 12V grid because most standard automotive electronics systems use 12V power.
As mentioned earlier, converters and converters need to manage several kilowatts of power, so it is necessary to have very complex and efficient electronics that optimize semiconductor devices and advanced packaging. International Rectifier (IR), which focuses on power management, believes that this semiconductor platform must meet the following requirements to meet the requirements of these new high-power electronic systems:
1) Greater energy efficiency in a variety of applications;
2) Higher current carrying capacity, with a current carrying capacity of 100A to 300A under typical voltage conditions of 600V to 1200V;
3) Better mechanical and electrical performance to ensure that it can withstand harsh automotive environments while meeting all safety and protection requirements for fail-safe design;
4) Lower electromagnetic interference and parasitic inductance, due to the high current and high voltage of the switch, will generate strong electromagnetic fields, including conduction or transmission of noise / electromagnetic interference, overvoltage spikes and other interferences affecting automotive sensitive electronic devices.
The five main platform elements shown in Figure 1 that address the above issues are discussed in detail below:
This article refers to the address: http://
Figure 1: Five â€œessential elementsâ€ to meet the power management needs of hybrid electric vehicles
1. High-efficiency high-voltage IGBT: In the voltage range of 600V to 1200V, this type of power switch is required to efficiently switch a large current of several hundred amperes. World-class trench IGBTs are more energy efficient under these high voltage conditions than MOSFETs. These devices have extremely low on-resistance at very high current densities. If a standard wire bond package is used, its performance will be greatly limited by this conventional assembly technique. IR therefore uses a patented solderable front metal process that allows the IGBT to be soldered on both sides, thus completely avoiding the use of wire bonds in the converter or converter module. This solution solves the two or more problems described above: the reliability and robustness of the wireless bonding assembly is greatly improved by avoiding the typical failure mode of "bonding wire drop". The potential failure mechanism is that the flux wears out, but it takes a long time and a high stress. Module manufacturers using this technology can use smaller devicesâ€”compared to state-of-the-art wire bond assembly solutions that operate at higher temperatures and withstand wider temperature variations. Figure 2 shows typical results of stress testing for advanced wireless bonding assemblies.
Figure 2: Comparison of power cycling with a wire-bonded IGBT based on a patented ceramic-based custom package with a wire-bonded double-sided soldered IGBT. The left and right panels show different temperature stress profiles, each of which represents a device under test.
In addition to improving robustness, devices with front solderable metals can improve other issues, including parasitic inductance, noise-generating ringing, and electromagnetic interference from high-current switching. By achieving a double-sided soldered connection, the inductivity is minimized or completely lost. IR's wire-bonded devices have proven to provide superior switching performance over any standard wire bond or plastic packaged device. For example, Figure 3 compares the fast switching performance of IR's patented DirectFET package with wire bonded plastic packaged devices.
Figure 3: IR's proprietary leadless bonded DirectFET package reduces parasitic inductance and ringing, and clearly demonstrates better electromagnetic interference performance.
2. Advanced packaging is another important factor in an efficient power management platform. As mentioned above, IR has introduced a very advanced packaging technology for the automotive industry. Placing a durable front metal layer on our silicon switches (MOSFETs, IGBTs) allows us to apply wire-bonded chip-scale power packages to all power switches. Direct-Packages offer excellent switching performance, virtually zero parasitic inductance, greater mechanical reliability and robustnessâ€”because wire bonding is avoided and both sides of the chip are dissipated. If there is a wire bond on one side, it is impossible to achieve double-sided heat dissipation. These packages address the main issues described above, enabling customers to design innovative control and power modules.
3. Fast switching devices are also a very important requirement for hybrid electric vehicle applications. Although motor-driven frequency converters typically have a switching frequency of 6 kHz to 10 kHz, DC-DC converters or other battery charging devices typically have a higher frequency range (100 kHz to 200 kHz) to improve buck/boost converter efficiency. And reduce the size of passive components (inductors / capacitors) in these systems. Unfortunately, based on the physical characteristics of its bipolar devices, IGBTs can achieve optimal performance at 10KHz switching frequency, but at high frequencies above 100kHz, special MOSFET, CoolMOS or Super Junction devices are required. . However, these devices have drawbacks such as extremely high cost and limited robustness. IR's automotive portfolio offers an alternative solution to these problems at a lower cost and with superior switching performance. IR's automotive DirectFETs set the benchmark for fast switching performance up to 250V. Higher voltage fast switching products require IR's proprietary WARP speed IGBT. Compared to typical high voltage superjunction devices, WARP speed IGBTs achieve higher switching frequencies at a better price/performance ratio. The new generation of automotive WARP speed IGBTs meets switching frequency requirements above 100 kHz and is therefore the ideal solution for high power DC-DC converters for hybrid electric vehicles.
Figure 4: IR's automotive grid drive is more robust and durable thanks to its proprietary process and design. These process characteristics and designs ensure absolute latching control of large IGBTs that generate high negative voltage spikes.
4. MOSFETs with high avalanche resistance are another important component of hybrid electric vehicle semiconductor platforms. Hard switching products often require MOSFETs to implement repeated switching by entering an avalanche mode. In avalanche mode, the voltage will substantially exceed the breakdown voltage, and highly accelerated carriers will flood into the PN junction region of the MOSFET at the breakdown voltage level. These highly accelerated "hot carriers" typically gradually damage the gate oxide. After a period of or repeated avalanche events, the MOSFET will experience irreversible damage. The threshold voltage drifts, the leakage current gradually increases, or sometimes the gate oxide layer breaks. IR's patented MOSFETs are particularly robust and reliable, enabling reliable repeat avalanche switching. These devices have proven to be robust when applied to hard-switching products with inductive loads such as motor drives. Combined with a leadless bonded Direct package, these devices set the benchmark for switching performance while ensuring superior silicon robustness.
5. Robust and powerful control IC for driving power devices. To help system designers complete the entire power-level development task with the required control ICs, IR has introduced a lineup of automotive driver IC portfolios. This portfolio is suitable for a wide range of topologies to meet the system requirements of advanced inverters, converters or power supplies. Proprietary high-voltage and low-voltage gate drive ICs for automotive applications with exceptional robustness and self-locking immunity. For applications with voltages less than 75V, IR has introduced patented intelligent power ICs that can handle much higher currents than analog mixed-signal ICs fabricated using cutting-edge BCD processes. For applications with voltages ranging from 100V to 1200V, a number of high-voltage junction isolation driver ICs with industry-leading negative transient voltage spike safe operating area (NTSOA) are also available, as shown in Figure 4. The failure mode of world-class drive ICs is often caused by high negative voltage spikes generated when high-current and inductive loads are used to perform half-bridge switching. IR's automotive driver ICs are rugged and self-locking, making them ideal for driving large IGBTs with high current densities. To meet the high gate drive current requirements, a proprietary buffer IC with up to 10A drive current capability has also been introduced.
Iphone X Snap3D Case is a protective iPhone X case,but also a 3D Viewer For Iphone X, It is a bare-eye VR viewer in phone case shape. When the users cover it on smartphone screen, he can enjoy 3D videos and games without wearing 3D glasses or VR headset. MOPIC Mplayer3D Application should be used together with the Snap3D, to search for 3D videos, 3D images, 3D games from Youtube, or search within the resources which are connected to Maplayer3D. It's light weight, easy to carry as well.
HOW TO USE THE SNAP3D Case AS A 3D SCREEN
The attached 3D screen on the Snap3D acts like 3D glasses.
To turn your smartphone into a 3D device, you need to first download the [Mplayer3D" application.
Then install the Snap3D on your smartphone screen and run Mplayer3D.
Enjoy the stunning stereoscopic 3D!
Iphone X Snap3D,Snap3D For Iphone X,Iphone X Snap3D Case,Iphone X Snap 3D Viewer
iSID Korea Co., Ltd , https://www.isidsnap3d.com