Hi there,
I consider using a step-down voltage converter based on MC34063 for powering my board using 5V USB input. Can I do that? I'm kind of worried, because, you know, SMPS... Will it somehow affect the functionality of Arduino because of its interference or output ripple? I would, of course, do everything to minimize the output spikes using LC filter, but maybe the processor still wouldn't like it. If there's anyone who has some experiences, please help.
You wouldn't think twice about connecting an Arduino to a PC, which uses a switched mode power supply.
I always thought that computers use linear regulation.
It's important because the Arduino powers and controls radio.
I suspect that almost all the Arduinos in use are either battery powered or are powered by switching power supplies. And that includes those powered over USB. Computers haven't used linear power supplies for a very long time.
Steve
Switching power supplies can and do affect radios, although its easy to assume there is no problem if you do not measure the effect. The affect can be very significant.
See here, USB power banks are switchers and I have seen similar problems with the small switchers you might on eBay for your Arduino project;
I'm gonna use LDO linear regulator.