Electromagnetic interference (EMI) reduces radio range, drastically decreasing the functionality of Internet of Things products. There are some local and intermittent EMIs that are eventually get addressed, thanks to the Wi-Fi protocols that come complete with automatic retry features. However, the interference coming from external sources are continuous in nature and can drastically reduce the range of a device’s onboard radio. This kind of interference has to be addressed by the right mechanical and PCB design. But what about the interferences that come right from your own product? Here are some useful tips that will help you minimize the EMI being emitted by your product and improve radio range:
Metal shields isolate circuits and prevent interference from reaching the antenna. At the same time, the antenna needs to be present outside the shield for receiving signals. So, shielding the interference sources is a better option than shielding the receiver. The Faraday cage is the best shielding solution available that provides a conductive box without any seams around the shielded circuitry.
However, you must develop metal shields with minimal contact resistance. And, there are several options to achieve this:
- Pick clear chromate instead of aluminum as it provides decent conductivity while resisting corrosion.
- Use an overlapping structure for an increased area and decreased contact resistance.
- Minimize contact resistance through gaskets that rely on screws outside the gasket for more reliable contact and compression force.
Select the Right Clock Frequencies
Certain circuits are never switched off, and the resulting interference affects the receiver’s sensitivity. In a controller board, for example, clock oscillator signal harmonics cannot be controlled easily and lead to interference. There is one clock of 19.2 MHz and another of 25 MHz in a Raspberry Pi design. While the latter falls between the popular non-overlapping Wi-Fi frequencies, the former falls inside the Wi-Fi frequency channels. So, even though the 25 MHz clock doesn’t solve the interference issue entirely, it does help to a certain extent.
Check for EMI Issues
Detecting interference issues becomes easier with a spectrum analyzer. Select one that has greater maximum frequency than the system radio’s highest frequency. When an antenna probe is connected to this analyzer, it can detect design problems and locate interference sources. No wonder this setup is used by the FCC to test for EMI compliance and radio performance issues.
Switching up the components of a PCB can work wonders when it comes to decreasing EMI interference and improving radio range. Sure, it’s better if you detect all the problems as early as possible, but it’s worth noting that following the steps above can result in a design that minimizes EMI emission and prevents interference from affecting other parts of the radio system. To know more about EMI shielding, click here. -LeaderTech
EMI shielding products are designed to protect electronics from the effects of interfering energy waves. But what happens when you use your equipment in an extremely damp environment? In such a situation, your priority should be to make your EMI shielding products corrosion-resistant. Rust or material deterioration will affect device performance due to high-frequency emissions interfering with your electronic gadgets. Here are a few ways to protect your equipment from corrosion:
Consider Surface Treatment
Paint or plate your electronic enclosures. It is essential to prevent corrosion, oxidation, rusting, and tarnishing. Maintain application aesthetics. When it comes to the flange surfaces, they require finishing for maximum protection against corrosion. There are a few factors to consider when employing finishing. You must ensure maximum shielding efficiency through corrosion-resistant and electrically conductive materials. You will require an additional coating for protecting shielded products from being corroded in high humidity surroundings.
Pick out Quality EMI Gaskets
Choose the right gasket material that can cut back the variation in electrochemical potential in relation to the metal structure. It helps to decelerate the corrosion process through a lower galvanic current. Opt for elastomeric gaskets that come with filler particles. The material will ensure both corrosion resistance and EMI shielding when exposed to metal. Use silver-plated copper, pure silver, and silver-plated aluminum fillers to ensure corrosion resistant EMI protection.
Opt for Additional Moisture Sealing
Spray or salt fog acting as an electrolyte may corrode your shielding materials. This is the reason why designers require secondary moisture sealing to get rid of it. To prevent corrosion in aircraft applications, a seal-to-seal design is the preferred choice of EMI shielding engineers. Similar gasket materials are used in every mating flange. Non-conductive sealers are used to stop water from seeping into your shielded products.
Choose the right EMI gasket material for protection against water, fog, or salt spray. The use of conductive coating and an additional moisture seal will keep corrosion under control for improved shielding effectiveness. If you want to learn more about our products, contact us today. -LeaderTechInc.com
Power Supply in Package (PSiP) Uses a Unique Design Based on a Patented, Two-stage Architecture that Relies on Capacitors to Handle the Bulk of the Power-conversion Work
SAN ANTONIO – APPLIED POWER ELECTRONICS CONFERENCE (APEC) – March 6, 2018 – pSemi Corporation (formerly Peregrine Semiconductor), a Murata company focused on semiconductor integration, introduces the PE23300, the industry’s only fully integrated LED boost power supply in package (PSiP) based on a charge-pump, switched-capacitor architecture that offloads most of the power-conversion work from the inductor to capacitors in the charge pump.
Powering up to eight LED strings at a total power level of up to 10 watts, the PE23300 is designed specifically to power LED backlight arrays in ultra-high-definition (UHD) and high definition (HD) LCD panels for 2-cell and 3-cell narrow-voltage DC notebooks, industrial and automotive displays.
“The PE23300 truly demonstrates pSemi’s power-semiconductor capabilities. The PSiP delivers a unique, two-stage architecture that brings ground-breaking conversion efficiency and small solution size and is packaged with Murata’s advanced, 3D-packaging technology and passive components,” says Stephen Allen, director of strategic marketing at pSemi. “All components required for operation are integrated into a 7.7 x 11.7 millimeter laminate-based LGA package, which is just 1.6 millimeters in height. To achieve this small size, we used a ‘die-in-substrate’ 3D-packaging technology. The low profile is also a result of our two-stage architecture that allows us to use a tiny chip inductor. All of this can be achieved with an efficiency that is on average about 5 to 7 percent higher than the competition, halving the losses in the LED boost.”
Power conversion creates a compromise between size and efficiency: The smaller the solution, the worse the efficiency. This compromise impacts OEMs trying to make next-generation, ultra-compact products, because they need both a very high conversion efficiency and a very small size at the same time. pSemi solves this problem with a novel, two-stage architecture that offloads most of the power-conversion work from the inductor to a virtually lossless charge pump and relies on small, multilayer ceramic capacitors (MLCCs) to do most of the work. As a result, the inductor – usually the largest and tallest component – can be reduced dramatically in size, and traditional wire-wound inductors can be replaced with chip inductors. This patented architecture was first developed by Arctic Sand Technologies, an MIT spin-out acquired by pSemi in March 2017, and commercialized this year.
Beyond the smaller inductor and higher efficiency, this architecture delivers several other key benefits for LED boosts, including full short-circuit protection and a very flat efficiency over the entire load range. Also, efficiency is virtually independent of the output voltage, and this allows more LEDs per string. With fewer strings, efficiency is optimized, and the display-bezel size can be reduced in width. pSemi’s PE23300 features low power dissipation – up to half that of competing products – that improves reliability and supports portable applications’ extensive battery run times.
The PE23300 features an input voltage range of 4.5V to 15V DC and powers up to eight strings of LEDs at up to 45V and 40 mA per string.
The PSiP provides full programmability via an I2C interface with settings stored in non-volatile memory or by using GPR pins. Dimming resolution is up to 12-bits resolution with an additional 3-bit dithering and can be either linear/logarithmic analog and PWM dimming or direct PWM dimming for maximum flexibility and resolution. The part features an LED brightness ramp up/down control with programmable ramp rate, linear/logarithmic ramp profiles and phase-shifted PWM dimming among active strings to minimize audible noise.
pSemi Corporation is a Murata company driving semiconductor integration. pSemi builds on Peregrine Semiconductor’s 30-year legacy of technology advancements and strong IP portfolio but with a new mission: to enhance Murata’s world-class capabilities with high-performance RF, analog, mixed-signal and optical solutions. With a strong foundation in RF integration, pSemi’s product portfolio now spans power management, connected sensors, optical transceivers antenna tuning and RF frontends. These intelligent and efficient semiconductors enable advanced modules for smartphones, base stations, personal computers, electric vehicles, data centers, IoT devices and healthcare. From headquarters in San Diego and offices around the world, pSemi’s team explores new ways to make electronics for the connected world smaller, thinner, faster and better. To view pSemi’s semiconductor advancements or to join the pSemi team, visit www.psemi.com.
The Peregrine Semiconductor name, Peregrine Semiconductor logo and UltraCMOS are registered trademarks and the pSemi name, pSemi logo, HaRP and DuNE are trademarks of pSemi Corporation in the U.S. and other countries. All other trademarks are the property of their respective companies. The pSemi website is copyrighted by pSemi Corporation. All rights reserved.