I have a couple questions, one is about identifying smps topology and the 2nd is about the 3rd winding in an example I found. I need to design a smps that can take Vin: 70V to 105V and output 5V at 1A I've chosen to use the mic9130 http://www.micrel.com/_PDF/mic9130.pdf On the front page of the datasheet there is a "Typical Application" schematic, which is not to far off from what I need to do, it's Vin: 36V to 72V Vout: 3.3V @ 4A So, I think I'll copy that design, but now I have to design a transformer... from the reading I've done about this, looks like one of the first things I need to know is the topology of my smps. That's my question, can anyone tell me the topology of this smps example? Looks like an isolated synchronous buck converter... or maybe a forward converter? Also I don't see how the third winding is supplying the stead voltage to Vcc, according to the datasheet Vcc operates between 9V -18V (pg 3) confusingly on pg 8 it says Vcc is typically 8.5V.... much thanks!
Xfmr design for smps
Started by ●March 8, 2012
Reply by ●March 8, 20122012-03-08
panfilero <panfilero@gmail.com> wrote:>I have a couple questions, one is about identifying smps topology and >the 2nd is about the 3rd winding in an example I found. I need to >design a smps that can take > >Vin: 70V to 105V and output 5V at 1A > >I've chosen to use the mic9130 http://www.micrel.com/_PDF/mic9130.pdf > >On the front page of the datasheet there is a "Typical Application" >schematic, which is not to far off from what I need to do, it's >Vin: 36V to 72V >Vout: 3.3V @ 4A > >So, I think I'll copy that design, but now I have to design a >transformer... from the reading I've done about this, looks like oneBuy an off-the shelf transformer: http://katalog.we-online.de/kataloge/eisos/index.php?language=en&vw=Uebertrager_fuer_AC_DC_Wandler>of the first things I need to know is the topology of my smps. That's >my question, can anyone tell me the topology of this smps example? >Looks like an isolated synchronous buck converter... or maybe a >forward converter? Also I don't see how the third winding isIts not forward. It is a flyback. I'd check this website for a solution: http://www.powerint.com/ -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico@nctdevpuntnl (punt=.) --------------------------------------------------------------
Reply by ●March 8, 20122012-03-08
On Mar 8, 3:08=A0pm, n...@puntnl.niks (Nico Coesel) wrote:> panfilero <panfil...@gmail.com> wrote: > >I have a couple questions, one is about identifying smps topology and > >the 2nd is about the 3rd winding in an example I found. I need to > >design a smps that can take > > >Vin: 70V to 105V and output 5V at 1A > > >I've chosen to use the mic9130http://www.micrel.com/_PDF/mic9130.pdf > > >On the front page of the datasheet there is a "Typical Application" > >schematic, which is not to far off from what I need to do, it's > >Vin: 36V to 72V > >Vout: 3.3V @ 4A > > >So, I think I'll copy that design, but now I have to design a > >transformer... from the reading I've done about this, looks like one > > Buy an off-the shelf transformer:http://katalog.we-online.de/kataloge/eis=os/index.php?language=3Den&vw=3DU...> > >of the first things I need to know is the topology of my smps. =A0That's > >my question, can anyone tell me the topology of this smps example? > >Looks like an isolated synchronous buck converter... or maybe a > >forward converter? =A0Also I don't see how the third winding is > > Its not forward. It is a flyback. > > I'd check this website for a solution:http://www.powerint.com/ > > -- > Failure does not prove something is impossible, failure simply > indicates you are not using the right tools... > nico@nctdevpuntnl (punt=3D.) > --------------------------------------------------------------why do you say it's a flyback? it doesn't seem to be based on a buck- boost topology to me, flyback would mean it could buck and boost the input voltage, seems like it can only buck....