I’m working on a project where I need to step down 24V to a stable 5V with a load current of up to 1A. I’ve decided to use a buck converter based on the LM2675 IC. Here is my schematic made in DipTrace:

Input: 24V (DC)
Output: 5V / 1A
Controller: LM2675
Switching Frequency: 260 kHz
I’m planning to use two capacitors:
Input Capacitor (C1): To smooth the input voltage and suppress noise.
Output Capacitor (C2): To smooth the output voltage and minimize ripple.
I have the following questions and concerns:
Type and value of the input capacitor: I’m considering using a 100 µF electrolytic capacitor with low ESR, but I’ve heard that ceramic or polymer capacitors might be better for high-frequency applications. Which type would be optimal for input noise suppression?
Type and value of the output capacitor: Given the need to minimize output ripple, should I use multiple low ESR ceramic capacitors or a single large electrolytic capacitor? Or perhaps a combination of both?
Impact of switching frequency on capacitor selection: How does the 260 kHz switching frequency affect capacitor choice? Should this be a factor when determining capacitance?
Temperature stability: The system will operate at elevated temperatures (up to 70°C). Which type of capacitor is best suited for these conditions?
I’d appreciate any advice or suggestions! I’m especially interested in hearing from anyone who has experience with similar circuits.
By the way, how do you like DipTrace 5? Has anyone tried working on it yet?

Possibly not the reply you want but since you asked for advice, then my advice is to buy them off ebay for under a fiver each. Actually the first hit I got was 6 units for £6.95 and these are adjustable.

Another device seriously worth considering is a USB-C Power Delivery Decoy Trigger dongle although in this instance I guess you have an existing 24v supply you wish to use but as USB-C is gaining more use and can handle more current than older USB standards then with a good USB-C PSU you can trivially generate a variety of voltages.

-Gordon

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Gordon Henderson.
See my Ruby 6502 and 65816 SBC projects here: https://projects.drogon.net/ruby/

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

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http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

It's interesting that you mention OS-CON, they are indeed incredibly efficient, especially in sensitive environments like the ones you describe. Electrical noise, especially in aeronautical systems, can really become a nightmare if the layout isn't optimized. OS-CONs, with their low ESR, really make a difference, especially compared with tantalums which, although reliable, tend to show their limits in terms of long-term stability in these applications. Speaking of switching regulators, I also think that integrated solutions like Pololu's can really simplify design, while retaining high energy efficiency. I've used them for a few DIY projects, notably to stabilize power supplies on embedded microcontrollers. It's not just about assembling the best components, but also about understanding how to minimize interference and maximize stability in complex systems. This kind of approach is fundamental to achieving maximum performance with minimum compromise.

Here, with a mass produced product that has both to cost the absolute minimum and not interfere with its own sensing systems... it's always a juggling act. I'll look into OS-CON - their series resistance is quoted impressively low...