开关电源的最好设计布局

simonlxh

[em15]
【文件名】:08318@52RD_开关电源的最好设计布局.pdf
【格　式】:pdf
【大　小】:116K
【简　介】:
【目　录】:When designing a high frequency switching regulated power
supply, layout is very important. Using a good layout can
solve many problems associated with these types of supplies.
The problems due to a bad layout are often seen at
high current levels and are usually more obvious at large
input to output voltage differentials. Some of the main problems
are loss of regulation at high output current and/or large
input to output voltage differentials, excessive noise on the
output and switch waveforms, and instability. Using the
simple guidelines that follow will help minimize these problems.

steveniyang

thanks.

john019

Inductor
Always try to use a low EMI inductor with a ferrite type closed
core. Some examples would be toroid and encased E core
inductors. Open core can be used if they have low EMI
characteristics and are located a bit more away from the low
power traces and components. It would also be a good idea
to make the poles perpendicular to the PCB as well if using
an open core. Stick cores usually emit the most unwanted
noise.
Feedback
Try to run the feedback trace as far from the inductor and
noisy power traces as possible. You would also like the
feedback trace to be as direct as possible and somewhat
thick. These two sometimes involve a trade-off, but keeping
it away from inductor EMI and other noise sources is the
more critical of the two. It is often a good idea to run the
feedback trace on the side of the PCB opposite of the
inductor with a ground plane separating the two.
Filter Capacitors
When using a low value ceramic input filter capacitor, it
should be located as close to the VIN pin of the IC as
possible. This will eliminate as much trace inductance effects
as possible and give the internal IC rail a cleaner voltage
supply. Some designs require the use of a feed-forward
capacitor connected from the output to the feedback pin as
well, usually for stability reasons. In this case it should also
be positioned as close to the IC as possible. Using surface
mount capacitors also reduces lead length and lessens the
chance of noise coupling into the effective antenna created
by through-hole components.

break-zhang

这也太贵了
我是个穷人不能卖的便宜点吗？

skyloo

没有中文的吗？英文的看不懂