questions on PWM ic chips....???

[jason 77]

In my never ending quest to get away from using pre-made power supplies for my projects "wall worts, black bricks, pc power" I came across some IC's that seem to me to be able to take the mains AC power and turn it into low voltage high current DC. I went to digikey to check some of them out.

FS7M0880TU-ND
FSDM0465REWDTU-ND
568-2441-5-ND

Are just a few I found on their site that look like they could be used in a power supply used for powering LEDS off of the mains. I started off with the idea of using a step down transformer and then rectifying the AC to DC but came across a couple problems in that design. The Transformers needed for anything over a few hundred milliamps seem to be quite large and the bigger problem is that I can't seem to find any transformers online that put out the power I want that don't cost a lot. These PWM IC chips only cost a few bucks, but I have no idea how to go about implementing them in a power supply circuit? Can anyone on here who actually knows how to read and understand the data sheets on these IC's help me understand if this idea would work or not? I had some electronic classes about 11-12 years ago so everything is a bit vague to me.. I find I have to relearn what I thought I already knew every time I try stuff like this... :mecry:

 

[jason 77]

I looked into these chips some more and I think that digikey's #568-2441-5-ND "manufacturer #TEA1620P/N1,112" is the best candidate, as it says on the data sheet that the applications for this chip are Chargers, Adapters, TV and monitor standby supplies, and PC peripherals. The example circuit the data sheet provides seems to use the least amount of external discrete components of all the other PWM ic's on digikey's website, but again I have no idea how to calculate the values of the external components as well as figuring out what kind of transformer they are using in the circuit below...

 

[jason 77]

Anyone have any idea how to do something like this?