mouser.com/vishay / 5
Learn More Learn More
IHDM-1008BC Edge-
Wound Through-Hole
Inductors
SQJQ184E TrenchFET
®
Gen IV MOSFETs
Figure 2: Simplified schematic of power stage
with only one phase. (Source: Vishay)
"The designer must ensure that
the inductor is rated for the
desired output current for both
self-heating and saturation."
also ensure that the inductor is rated for the desired output
current for both self-heating and saturation.
Vishay IHDM inductors are a great choice for these inductors
because they have a good combination of low DC losses, low
core loss (AC losses), and the best saturation performance of
any of the inductor material choices. The IHDM series covers
a wide range of inductance values, from 0.1uH to 200uH, with
current handling capability from just a few amps to several
hundred amps. These inductor series are also available in
several materials that allow efficient operation at frequencies
from 100KHz up to 5MHz.
The input and output currents are measured using current shunts
R1 (2mΩ) and R2 (0.5mΩ) in Figure 2, in this case, the Vishay
WSLP3921 series. This is necessary to distribute the current
equally to the individual modules when using a multistage design.
The Vishay Power Metal Strip
®
technology was selected for its
high temperature capability and long-term stability.
The combination of C1/L1 (IHLP4040) and C6/L3 (IHLP5050) in
Figure 2 makes up the input/output filter that suppresses the
ripple current. In this case, the Vishay IHLP
®
series was used for
the filter inductors for the same reasons outlined above for the
main storage inductor.
The capacitors next to the half bridge (C3/C4 in Figure 2) limit
the peak current. Because of the high ripple currents, multiple
capacitors with low equivalent series resistance (ESR) are
connected in parallel. These are preferably multi-layer ceramic
capacitors (MLCCs). An NTC thermistor such as the Vishay NTCS
series that features polymer terminations for enhanced reliability
under thermal stress, allows the temperature to be monitored and
the power consumption to be reduced on demand. This Vishay
reference design performance is very impressive as it provides an
efficiency of approximately 97 percent.
The right design and component selection is critical for
DC/DC conversion applications that require shifts in electrical
requirements for 48V systems while withstanding the harsh
automotive environment. ▼
