Page 12 - PEN eBook July 2023
P. 12
Cover Story — Design
The number of hours the battery
will last is shown in Figure 4 based
on the efficiency of the DC/DC
converter. A jump in efficiency
from 20% to 85% results in an over
400% increased battery lifetime.
This results in longer operating
time between charges, longer
intervals between maintenance,
etc.
POWER LOSSES AND
Figure 4: Battery lifetime dependency on the DC/DC controller efficiency
THERMAL DERATING
Another impact of higher efficiency,
especially relevant in space-constrained applications, is a lower temperature rise of the converter.
By comparing the derating curves of the VDLM with an LDO in a similar package design, the negative
effect of the losses on the performance becomes apparent.
Figure 5 shows the negative influence of the power dissipation on the output current capability of
the LDO. The LDO used in the comparison is rated for V = 40 V and I = 1 A.
IN OUT
Figure 5: Derating comparison between WPME—VDLM 171013801 and LDO
12 JULY 2023 | www.powerelectronicsnews.com
