Vishay’s new “IHLP Core Loss Calculator” is a free tool that assists designers in selecting the proper IHLP inductor based on the operating conditions of their circuit. This tool will simulate the losses in the inductor, including core and both AC and DC copper losses. The temperature rise and final component temperature will also be predicted based on the estimated losses. This tool will allow designers to compare several different inductors, both in size and value, to assist in the selection process. The calculator can be used for buck, boost and buck/boost style converters.
The calculator requires only six inputs: input voltage, output voltage, output current, frequency, ambient temperature and inductance. The calculator will do the rest based on these inputs. Inductance can be selected by using the “radio” buttons on the left hand side.
All designs should be verified in circuit as this tool is for simulation only.
IHLP inductors have a recommended maximum component temperature of 125 °C. Subtracting the ambient temperature will give us the maximum allowed temperature rise for the part. If this number should exceed 40 °C it is recommended that 40 °C be used for the allowed temperature rise. Core losses should be limited to ≤ 1/3 of the total losses to mitigate any aging effects associated with the powdered iron in the core at temperatures exceeding 125 °C. The recommended range for the ripple current is 30% to 50% of inductor current. This is based on a trade off of inductor size and cost versus output capacitor size and cost. The maximum peak current should be kept below the Isat value of the selected inductor, although it can be exceeded with caution due to the soft saturation characteristics of the powdered iron core material. The calculators are based on operation in the continuous conduction mode only, information determined in the discontinuous conduction mode should be considered suspect and in need of verification by the user.