IHLP® LOSS CALCULATOR HELP FILE
The purpose of this calculator is to estimate the losses in the Vishay IHLP series inductors used in continuous mode power converters. Both copper and core losses are estimated. The program also may be used to estimate temperature rise, but you may experience results different from what this program predicts.
Inputs: Eight inputs must be supplied by the user of the calculator. Data must be entered into the yellow cells only.
- Enter the inductance by clicking on one of the radio buttons on the left side.
- Enter the frequency of the circuit.
- Enter the DC output current of the converter.
- Enter the ambient temperature. The program uses this to calculate the final resistance of the inductor and the final component temperature.
- Enter the input voltage of the converter.
- Enter the output voltage of the converter.
- Enter the switch drop voltage VSW.
- Enter the diode or sync FET voltage drop VD.
Once entered, your inputs will remain as is until a new input value is entered. To change inductance used, click a different inductance button. Clicking the button sets up the calculator with new internal data for the part specified and immediately updates the calculator, including the graph.
Outputs: The outputs of the calculator are displayed in the blue cells, they are summarized below.
- ETckt: The volt-microsecond product of the converter circuit.
- F(eff): This is the calculated effective frequency of the circuit used for the determination of core loss. The program takes into account the shape and amplitude of the current ripple when it calculates core loss.
- Res: Resistance of the inductor at the temperature specified in the inputs.
- Imax: The peak current of the inductor at the top of the ripple.
- Imin: The instantaneous current at the bottom of the ripple.
- Iripple: The change of inductor current from the bottom of ripple to top of ripple = Imax - Imin.
- Duty: The percentage of time that the switch is on.
- Pcore: Core loss in watts.
- Pdc: Conductor loss due to dc resistance in the inductor in watts.
- Pac: Conductor loss due to ac effects in watts.
- Ptot: Total losses in the inductor = Pcore + Pdc + Pac.
- Temp. Coeff: The rise in temperature in °C per watt of dissipation. This is based on lab tests performed on sample inductors using the change of resistance method. Your thermal environment and that used in our lab may be different.
- Temp Rise: This is the increase in inductor temperature above ambient.
- Comp Temp: The ambient temperature plus the temperature rise. This is the estimated temperature of the inductor.
- Iind: This is the DC current that the inductor sees in the boost and buck-boost converter topology, in buck converters the inductor current is equal to the output current.
- ET100: Volt-microsecond product of the inductor at 100 gauss.
- Bpk: Peak flux density of the circuit based on operating conditions specified.
