New MLCC Capacitor stabilizes ESR values & simplifies circuit design

TDK Corporation will feature its multi-layer ceramic chip capacitor with a new internal structure that allows Equivalent Series Resistance (ESR) values to be set to any value within a specified range at the Applied Power Electronics Conference in Washington D.C.

Available in 0603 and 0805 configurations, the ESR is controlled by a structure approach. Due to smaller and increasingly advanced functions of electronic devices such as PCs and mobile information terminals, manufacturers are making strong demands for reduced mounting areas and miniaturization of components. As a result, power supply circuits on boards with ever-higher mounting densities must combine multiple capacitors of different types. In addition, impedances must be adjusted over broad frequency ranges.
The effects of the minute electrical resistance elements present in the capacitors themselves can cause interference among multiple capacitors depending on the frequency, which can lower noise suppression effects. Generally, it is necessary to use even more components to control these effects. To respond to these demands, TDK used its strengths in materials technology and multi-layering technology to develop a capacitor with a new internal structure that allows ESR values to be set while maintaining the same capacitance as standard products. Also of importance, the ESL value can be held constant or even lowered in some cases by this new structural approach.
Because the ESR values of capacitors located in the vicinity of the CPU can be set, there are smaller changes in impedance between the power supply and the CPU over a broad range of frequencies as well as voltage variation limiting effects. Limiting the variation in voltage stabilizes the current signal and eliminates effects on other circuits.
These new capacitors are suitable for use in applications that require high power supply quality such as communication base stations and high-end PCs. Although the sizes are the same as standard products, resistance has been adjusted to be up to 1200 mO for the 0603 product and 500 mO for the 0805 product, and the ESR values can be set to any value within a specified range. By adding resistance components, the variation in impedance over frequency can be lower than standard products, which may contribute to reducing the number of components needed. The mounting method is the same as that for two-terminal products, making switching from existing components easy.

For additional information on TDK visit the web site at www.tdk.com