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Multisim 11 is the latest version of its circuit simulation software, with specialized editions for both hands-on learning and professional circuit design. The easy-to-use Multisim software delivers a graphical approach that abstracts the complexities of traditional circuit simulation, helping educators, students and engineers employ advanced circuit analysis technology. The academic edition of Multisim 11 incorporates specialized teaching features and is complemented by circuits textbooks and courseware. This integrated system helps educators engage students and reinforce circuit theory with an interactive, hands-on approach to investigating circuit behavior. Multisim 11 Professional helps engineers optimize circuit designs, minimize errors and reduce prototype iterations. When combined with the new NI Ultiboard 11 layout and routing software, Multisim provides engineers a cost-effective, end-to-end prototyping platform. Its integration with NI LabVIEW measurement software also helps engineers define custom analyses to improve design validation…

Breadboarding a new circuit is a key skill and an important step in many projects—especially early on, when you need to move wires around and substitute components. But that very flexibility also makes it easy to knock wires out. Eventually, if your project is a keeper, you’re going to want something with a bit more permanence. Printed circuit boards (PCBs) solve all those shortcomings. But most people don’t even consider translating a one-off project into a PCB design. For one thing, PCB fabrication has traditionally been expensive, viable only in commercial quantities. (One alternative is to do it yourself with etches and silk screens, a messy and time-consuming process.) Also, there are technical constraints involved with PCB designs that are daunting to the casual hobbyist. But it turns out that nowadays you can produce a professional PCB very inexpensively.

Harmonic balance (hB) analysis is a method used to calculate the nonlinear, steady-state frequency response of electrical circuits. It is extremely well-suited for designs in which transient simulation methods prove acceptable, such as dispersive transmission lines in which circuit time constants are large compared to the period of the simulation frequency, as well as for circuits that have a large number of reactive components. In particular, harmonic balance analysis works extremely well for microwave circuits that are excited with sinusoidal signals, such as mixers and power amplifiers...

LED luminaires require precise power and heat management because LEDs convert most of the electrical energy they receive into heat rather than light. Without adequate thermal management, this heat can degrade the LED's life span and affect color output. Also, LEDs can fail short because they are silicon devices, so they may require fail-safe backup in the form of overcurrent protection. Resettable PPTC (polymeric-positive-temperature-coefficient) circuit-protection devices have demonstrated their effectiveness in a variety of LED-lighting applications. Like traditional fuses, they limit current after they exceed specified limits. However, unlike fuses, PPTC devices can reset after the fault clears and the power cycles.

The design of a generator system requires many hours of detailed planning with the goal of creating an extremely reliable backup power source. Properly installed, the system will deliver the intended level of reliability. However, if incorrectly wired, the system can become a problem for both the owner and the manufacturer. While the generator installation can be handled by a range of people, from a trained technician to the typical homeowner, wiring mistakes can occur. Installation includes working with 120 VAC split phase, 240 V line voltage, along with low-voltage signals below 50 V. A small and easily made mistake, such as miswiring high voltage to low voltage, will destroy sensitive electronics quickly and may render the equipment inoperable. Thus, a resettable overcurrent and overvoltage solution capable of handling line voltage, electrostatic discharge (ESD), electrical fast transients (EFT), and current surge is required to protect low voltage interface circuits against this problem.

Three-dimensional microchip designs are making their way to market to help pack more transistors on a chip as traditional scaling slows down. By stacking logic chips on top of one another other or combining logic chips with memory or RF with logic, chipmakers hope to sidestep Moore's Law, increasing the functionality of smartphones and other gadgets not by shrinking a chip's transistors but the distance between them. "There's a big demand for smaller packages in the consumer market, especially for the footprint of a mobile phone, or for improving the memory bandwidth of your GPU," says Pol Marchal, a principal scientist of 3-D integration at European microelectronics R&D center Imec. On 9 February, at the IEEE International Solid-State Circuits Conference (ISSCC), in San Francisco, Imec engineers presented some key design challenges facing 3-D chips made by stacking layers of silicon circuits using vertical copper interconnects called through-silicon vias (TSVs). These design constraints will have to be dealt with before TSVs can be widely used in advanced microchip architectures, Marchal says.

Tiny semiconductor dots could lead to a new type of circuit based on magnetism rather than current flow. At least that’s the hope of researchers who’ve made the dots and are hoping to build them into a workable device. ”We want to make it into a so-called nonvolatile transistor,” says Kang Wang, head of the Device Research Laboratory at the University of California, Los Angeles. Such a ”spintronic” transistor would retain its logic state in the absence of current and require less power to switch a bit, reducing the electrical power required by a computer chip by as much as 99 percent. Wang’s research, supported in part by Intel, was published in March in the online version of Nature Materials. Where electronic transistors rely on the presence or absence of current to register the ones and zeros of digital logic, spintronic transistors depend on ”spin,” a quantum characteristic of the electron. Picture the electron as a rotating globe. When the north pole is pointing upward, that’s spin up; when pointing the other way, it’s spin down. When the spins of most electrons are aligned, the material is magnetic. When their spins are random, the material isn’t. An applied current can align or randomize the spins, allowing for spin-based switches.

With the introduction of the WEBENCH Online Design Environment in 1999, National Semiconductor made it possible for design engineers to create a reliable power supply circuit over the internet in minutes. The user specified the circuit performance and the WEBENCH Toolset delivered. Today, WEBENCH Designer creates and presents all of the possible power, lighting, or sensing circuits that meet a design requirement in seconds. This enables the user to make value based comparisons at a system and supply chain level before a design is committed. This expert analysis is not possible anywhere else.

Simple mathematical analysis shows that the best answer to address this problem is to  select a CR ratio QGD/QGS1 that is less than 1. Other factors to consider for preventing C dv/dt induced turn-on include low driver-sinking impedance (<1 Ώ), a FET design with intrinsically low RG, an externally-applied G-S capacitor and Q2 packages that minimize parasitics and voltage ringing.

Ted Marena of Lattice Semiconductor Corp., points out that designers of digital systems are familiar with implementing the 'leftovers' of their digital design by using FPGAs and CPLDs to glue together various processors, memories, and standard function components on their printed circuit board. In addition to these digital functions, FPGAs and CPLDs can also implement common analog functions using an LVDS input, a simple resistor capacitor (RC) circuit and some FPGA or CPLD digital logic elements to create an analog to digital converter (ADC).