Application note from Vishay on power and voltage limitations of solid tantalum capacitors for both low and high frequency applications. Link here (PDF)
Solid tantalum capacitors are preferred for filtering applications in small power supplies and DC/DC converters in a broad range of military, industrial and commercial systems including computers, telecommunications, instruments and controls and automotive equipment. Solid tantalum capacitors are preferred for their high reliability, long life, extended shelf life, exceptional stability with temperature and their small size. Their voltage range is 4 to 50 volts for the most common types. Tantalum chip capacitors for surface mount applications are manufactured in very small sizes and are compatible with standard pick-and-place equipment.
App note from Vishay about constant voltage (CV) pulse charging as the most cost-efficient solution to use on Hyrid capacitors. Link here (PDF)
Rechargeable energy storage solutions are of high interest because of their flexibility, low maintenance requirements, and reduced cost over their life-cycle.
For compact applications, classic electrolytic capacitors are environmentally friendly alternatives and available for a wide range of rated voltages. However, they soon reach their energy storage limit with output requirements exceeding a few 100 mWs.
Electric double-layer capacitors (EDLC) offer high power and energy density, as well as long working life, but are limited to low working voltages in the same range as batteries. Electronic systems require a compromise between these technologies, namely solutions that combine the advantages of classic batteries and double-layer capacitors without the limitations.
Tantalum comparison to other types of capacitors shows stable capacitance in this app note from Vishay, Link here (PDF)
Tantalum capacitors in general – and Vishay’s 298D/TR8/TM8 MicroTan tantalum capacitors in particular – demonstrate very stable performance over the DC voltage (bias) applied in an application. At the same time, the majority of capacitors utilizing ceramic or polymer dielectrics (monolithic ceramic, disc ceramic, MLCC, polyester, film, etc.) demonstrate significant shift in both directions – sometimes 40 % to 50 % or higher
App note from Vishay on the advantages of using Through-Hole mounting. Link here (PDF)
Most electronic gadgets are designed to interface with humans, and we humans are very abusive to most electronic devices. We drop them, poke them, open and close them, and in general feed stuff into and out of them.
It is well understood that a through-hole connection to the PCB is mechanically stronger than most surface-mount connections. By comparison, the strength of the bond that holds a surface-mount component to the PCB is limited to the strength of the solder joint that holds it to the surface of the laminate. As parts get smaller, so does the amount of solder and thus the strength of the bond.
App note from Vishay on PCB thermal management specifically on components like SMD resistors, where if allowed a design change (e.g. change in SMD size or change in more heat tolarant ones) must be implemented in order to squeeze more thermal capability. Link here (PDF)
Thermal management is becoming more important as the density of electronic components in modern printed circuit boards (PCBs), as well as the applied power, continues to increase. Both factors lead to higher temperatures of individual components and of the entire assembly. However, every electrical component in an assembly has to be used within its prescribed operating temperature limits due to its material properties and reliability aspects. In this application note, experimental results are provided in order to prevent overheating of electronic devices such as surface-mount resistors.
App note from Vishay on variable resistors primer. Link here (PDF)
A potentiometer is a mechanically actuated variable resistor with three terminals. Two of the terminals are linked to the ends of the resistive element and the third is connected to a mobile contact moving over the resistive track. The output voltage becomes a function of the position of this contact. Potentiometer is advised to be used as a voltage divider.
App note from Vishay about energy meter circuits and the use of leaded resistors on them. Link here (PDF)
An electric meter or energy meter is a device that measures the amount of electrical energy supplied to a residence or business. It is also known as (k)Wh meter. The main unit of measurement in the electricity meter is the kilowatt-hour which is equal to the amount of energy used by a load of one kW over a period of one hour.
A technical note about Thin Film fuses from Vishay. Link here (PDF)
Thin film technology is an established technology for high-grade passive components, which has been proved and refined over decades. Its advantages in terms of accuracy, repeatability and stability are appreciated in mass production for billions of thin film resistors every year. Chip fuses produced in thin film technology now deliver similarly predictable properties in terms of the stability and repeatability of the fusing characteristic. With this proven technology embodied in next-generation safety devices for overcurrent protection, power electronics designers can achieve higher levels of safety and performance in new product designs.
SSR or solid state relays input resistor recommendation app note from Vishay. Link here (PDF)
Solid state relays (SSRs) are commonly driven by TTL or buffered CMOS logic gates. These gates, when used to sink current, provide adequate drive for SSRs. An open-collector output is not required to drive the SSRs, but it can be useful to perform a logic OR function.
A quick recommendation for 5 V power supply operation of most SSRs is to use a 560 ohm resistor. This combination provides an LED current range of 5 mA to 9 mA, thereby optimizing LED current, surge capability, and turn-on/off times. This calculation has taken into consideration power supply variations, temperature variations from – 40 °C to + 85 °C, and manufacturing variations. It uses a 10 % tolerance, 300 ppm/°C input resistor. Likewise, for operation to only 70 °C, a 680 ohm resistor would suffice.
Application notes from Vishay on effective heat dissipation for their aluminum nitride utilized resistors. Link here (PDF)
The intent is to discuss a few techniques to manage the heat that is generated by high-power surface-mount resistors and the effects they will have on design space, complexity, and cost.