In this article, we'll explore nine expert capacitor tips that will help you navigate the complexities of capacitor selection, application, and maintenance.
What are the selection considerations of output capacitors?
This application note describes the selection considerations of output capacitors, based on load transient and output impedance of processors power rails. Presently, there are no specific tools available for non-Intel processor output capacitors selection in multiphase designs.
How to select capacitors?
Aside from the capacitance, another thing to consider on how to select capacitors is the tolerance. If your application is very critical, then consider a very small tolerance. Capacitors come with several tolerance options like 5%, 10% and 20%. It is your call which is which.
How to select bulk input capacitors?
There are two key factors for selecting bulk input capaci-tors: 1) overshoot and undershoot requirement of transient response; and 2) allowable ripple current requirement. The ESR of the bulk capacitor (ESRB) and the capaci-tance (CB) need to meet the transient response requirement.
Do capacitors meet non-Intel processor requirements?
Part 2 will describe capacitor types and value to meet output impendence requirements, and also high rate repetitive load transient specifications. Analytical and experimental results show that output capacitors selection is optimized for load transient and output impedance, to fulfill non-Intel processor requirements.
What type of capacitor should I use?
In both cases the capacitors should have low leakage current and have adequate precision. The best choices for feedback capacitors are class 1 ceramic capacitors, polystyrene film capacitors, and for high temperature applications, polycarbonate film capacitors.
What type of capacitor should I use for bypassing?
Bypassing capacitor selection depends on your requirement specifications. Low-frequency applications can be served by aluminum electrolytics or tantalum electrolytics. Class 2 ceramic capacitors provide a volumetric efficiency advantage for non-critical applications like higher frequency bypassing.