Seeking Guidance to Design High-Power SMPS with ICs like UC3843, TL494, IR2153 - Page 1
Forum section: electronics / beginners

author: Alen Hodžič
author_rank: Newbie
timestamp: October 08, 2025, 07:13:08 pm
content: Hi everyone,I’m an electronics hobbyist hooked on channels like DiodeGoneWild, EEVblog, and other YouTube creators, and I’m diving deep into switch mode power supplies (SMPS). My ultimate goal is to design high-power SMPS from scratch, covering all topologies—buck, boost, flyback, half-bridge, and more.I’ve read a couple of SMPS design books to understand the theory and have experimented with circuits, including some using the MC34063 IC. However, I’m struggling to find reliable, complete design schematics for popular ICs like the UC3843, TL494, and IR2153. I diligently read datasheets, but they often lack full, practical schematics to guide me. I hate copying unreliable circuits from random sources online, as I want my designs to be robust and efficient.I’m seeking advice from this community on how to progress toward designing high-power SMPS. Can anyone recommend trustworthy resources, practical projects, or design tips for working with these ICs? I’m particularly interested in how to translate datasheet info into complete, high-power designs. I’m not looking to buy pre-made solutions—I want to master the process of building them myself. Any guidance, component recommendations, or mentorship would be greatly appreciated!Thanks, AlenI want to become as good as Diodegonewild someday hopefully. But I dont understand how should my approach be.

author: Whales
author_rank: Super Contributor
timestamp: October 08, 2025, 07:44:12 pm
content: I am by no means an SMPS expert.The UC3843 and TL494 are quite old and widely cloned. This means that it's easy to find transient SPICE models for them and simulate your circuits. I have been doing this quite a bit this year to test out different toplogies, sensing methods and control loops. EDIT:Some example sims.that topic doesn't show the aforementioned chips, but instead my own discrete controllers, woops(And of course when I've actually built the circuits there have been differencesBut not too drastic)QuoteYes.For narrow usage case SMPS ICs, like small synchronous buck ICs, the datasheet examples are usually exhaustive or close enough.For very generic SMPS control ICs, like the ones you list, the examples are seldom exhaustive.In particular it's worth noting whether or not the manufacturer appears to intend for their chips to be used for transformer-coupled or inductor-coupled circuits. Transformer coupling is mostly done for "offline" (input is rectified mains 110/240V) circuits and makes some parts of the SMPS control IC much simpler, such as how it senses current. Converting these for use with an inductor can require complex current sensing techniques.The internal equivalent circuit diagrams for these chips are very useful to understanding how they work. The UC3843 looked like magic to me for a long time, there are quite a few odd bits in it

author: jwet
author_rank: Frequent Contributor
timestamp: October 09, 2025, 06:39:38 pm
content: The parts are from a different ERA and are one of the reasons that simple to use switchers from National, Maxim and LTC thrived in 90's and on. They take real expertise to design with. You have to be comfortable with bode plot type compensation and analysis.Unitrode, which was later acquired by TI, had application seminars and amazing FAE's that helped people design this in back in the day. Some of the collateral and application book from those days might still be around- 80's through 90's. These parts weren't used by a ton of people, they were used by specialists who the suppliers had relationships with and helped. Other application data from this era that could help would be Siliconix, Vishay, Fairchild and International Rectifier.Here is one old Unitrode App Note that TI carried forward. You can get an idea of the quality and depth of the expertise required here.https://www.ti.com/lit/an/slua143/slua143.pdf?ts=1759987047966There are specialty training seminars by Ridley and others that show the way. The training is expensive and you'll want to buy a Riddley network analyzer which is also big bucks.Good luck. If you succeed, you'll be very valuable to a lot of companies. In my experience, big companies usually had one guy who could REALLY do this kind of work.

author: mtwieg
author_rank: Frequent Contributor
timestamp: October 10, 2025, 05:50:54 pm
content: These components are extremely general-purpose, which is why their documentation typically won't include reference designs for entire power supplies. Much like how a general-purpose opamp datasheet usually won't include a reference design for an audio amp or a fiber optic receiver or something.If you look at datasheets of chips with integrated power FETs, then you're much more likely to see detailed reference designs.It's unclear whether you're looking for references on power electronics (i.e. the actual power circuitry) or on control and controllers. The two are very different topics (though they do overlap in some places).Seconding the recommendation to read old Unitrode app notes. They cover a very wide array of topics covering both control and power circuitry, and all of it is still relevant.