The other attributes that determine the right inductor solution are typically calculated values from the information provided on the datasheets. As the schematic in the center of this slide shows; an inductor having a series resistance value “R”, an inductance value “L” and a capacitance value “C”. Q (efficiency, also known as the “quality factor”) is a measure of the relative power losses in an inductor and an efficiency indicator as a ratio of energy stored to energy wasted by the component. Q describes the energy storage capacity of a power inductor. This parameter is related to the frequency of measurement and inversely proportional to its resistive losses at the same frequency. The SRF (Self Resonant Frequency) is the frequency in MHz where the inductor’s distributed capacitance and inductance reach a perfect match, where the parameters cancel each other and the inductor will act as a resistor with high impedance. Below the SRF frequency inductors act normally however, over the SRF frequency the inductor will resemble a capacitor behavior.