Hi MPS team,
In my application used the MPQ24833-B, input voltage is 24V-30V, Output load is 3 LED connected in series Each 9v Forward voltage drop, Forward current is .9A, how to calculate the power dissipation, you have any calculation sheets or toll available, please let me know , For PD if IC we need consider the Inductor, Schottky Diode PD also need to consider ?
Hello Mathan, apologies for the delayed response on this.
The first thing to consider here on an overhead level would be the dissipation of the 3 series LEDs here. 3 LEDs in series with a forward current of 0.9A and forward voltage of 9V yields a total voltage of 27V of total series drop.
So P_LED = 27V x 0.9A = 24.3W.
The calculation above is the IC power dissipation, not necessarily the loss.
The inductor and Schottky diode loss is good to consider, but they are system losses that are separate from IC power dissipation. Other as aspects of loss to consider here would be the following:
A practical way to estimate loss here would be Ploss_total = Pout (1/efficiency - 1). You can use the following efficiency plot as a reference:
