Need a SMPS solution.

[Boscoe]

So I need a compact SMPS for a project of mine. Space is at a premium and so I need to design it myself and integrate it onto my PCB ideally.

Requirements:

- Switch frequency 100kHz<
- Two rails at 28V 2A each.
- Low noise (good enough for audio).
- Small.
- 230Vrms input.
- PFC unnecessary.

The system is going to have a standby 3V3 rail so I'm thinking I could use that rail to drive a quick MCU or a small FPGA to use as the controller, I could I have a fast ADC in there too. The I use a gate driver IC from IR and design myself a small transformer. Easy? Not sure, I've never designed a SMPS before, I've always avoided it, but I'm capable.

I would prefer to use an off the shelf IC but they all seem quite outdated and don't usually have 230Vrms operation reference designs.

Thanks

[NiHaoMike]

Have you looked into the Power Integrations switcher chips? That said, you'll be better off using off the shelf solutions whenever possible.

[DanielS]

Doing an AC-DC converter as your first SMPS attempt seems excessively ambitious and kind of dangerous.

If you want a minimum component count solution, look at things like the TOP250. That device has nearly everything you need for the primary side of things. As far as noise goes, you can take care of most of that with a Pi-filter but then that means more space on the power supply board.

[Boscoe]

Have you looked into the Power Integrations switcher chips? That said, you'll be better off using off the shelf solutions whenever possible.

They look interesting. I am quite biased towards doing my own for experience etc. It looks fairly straight forward with the difficult bit getting it safe and reliable. This part scares me because I want to be able to use it in my house without having to turn it off all the time.

[Boscoe]

Their information is good and there's software tools!