Technical Articles / Whitepapers

Low Inductance Capacitors for High-Speed Decoupling Written By: Robert Lu Abstract: Modern integrated circuits (IC’s) consume power at rapidly varying rates due to the density of circuits on-board and the extreme speed at which they can operate. Power supplies are required to respond to these changes in load current while maintaining a constant operating voltage. This task is becoming increasingly difficult as the complexity of power distribution networks grows and printed circuit board (PCB) design requires optimization for parasitic inductance and capacitance. Therefore, any power supply performance slack must be absorbed by the all-too-common decoupling capacitor. As shown in Figure 1, a decoupling capacitor is simply an additional parallel capacitance that provides a stable voltage and source of current when

Variability and Tolerance of Ceramic Capacitors Written By: Robert Lu Abstract: The multi-layer ceramic capacitor (MLCC) is one of the most common capacitor varieties found in electronic design. It offers a wide range of bulk capacitance and voltage tolerance in numerous form factors at relatively low cost. While these devices have become commonplace in the designers’ tool chest, they exhibit some often overlooked peculiarities. Of primary concern is the sensitivity of effective capacitance to several environmental factors, including temperature, applied bias voltage, and age. If these factors are unaccounted for, the risk of product failure becomes very real, especially in manufacturing variability and overall tolerance stack-up.

Electrostatic Protection Using Ceramic Capacitors Written By: Oliver Zimmermann | John McCarry Abstract: Any conductive interface between an electrical circuit and the outside world introduces the possibility of damage through electrostatic discharge (ESD). Accumulated static charge on a person, a cable, or any similar surface can readily dissipate its stored potential energy upon contact into sensitive components resulting in highly destructive currents. Ideally, varistors and TVS diodes only activate to protect the circuit when a high voltage is present and impart no parasitic effects during normal operation. For high-speed data lines, in particular, it is critical that the protection device introduce as little capacitance as possible (Electronic Design). TVS diodes and varistors are therefore specified not only by their voltage

Key Parameters for Designing Ceramic Capacitors in SMPS Circuits Written By: Kevin Cho Abstract: Capacitors are ubiquitous and indispensable components of electronic circuits used for a plethora of uses. For engineers looking to design multilayer ceramic capacitors (MLCCs) in switch-mode power supplies (SMPS) such as Buck and Boost converters, some essential parameters to be considered include the ripple current capability, ripple voltage, and power dissipation. Using the KYOCERA AVX SpiCalci10 model simulation tool for SMPS capacitors, this whitepaper will outline various MLCC characteristics, AC current capability, and other considerations for circuit design.