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WEBENCH-POWER-DESIGNER: Need help from an expert to concive one switching dual power pcb via webench

Part Number: WEBENCH-POWER-DESIGNER
Other Parts Discussed in Thread: TPS54560, LMZ34202, LM2587

Hello! 

wanted to ask is there someone who can help me to design one power supply pcb:

i want to use an appropriate buck converter or simple switch to transform incoming 14-24 DC and have dual output on +12V  and -12V  and also 5V (which will be via one regulator I imagine) so in fact there will be triple output

all that with at least 900 mA or 1A or more at output (can be less for 5V)

would like to be not bigger than 7cm X 4,5cm, with good efficiency and silent.

if  that is possible and if You find time for this, i will be grateful for your kind help since I'm not an engineer (so not understand everything on webench application) 

Thanks in advance!

Jovan

  • TI can probably not design this circuit for you, but we can certainly aid you in component selection and design. Do you have access to schematic capture and PCB layout software? How do you intend to fabricate your design and how may do you intend to produce? What is your end application and what do you intend to power with this circuit? It may be possible that we already have a reference design which we can provide. Let me check our archives. Just FYI, I am currently on business travel and may not get a chance to search for a couple days. Maybe someone else may also have some ideas.
  • I searched our reference designs and did not find anything to match. You could do a coupled inductor using TPS54560 for +/- 12 V. See this application note:
    www.ti.com/.../slva369
    You could use any number of simple buck converters for the 5 V output, maybe LMZ34202.

    Alternately you could shop for a commercial off the shelf solution. I'm sure there are several vendors who sell triple output modules. I would probably start with Digikey.
  • Hello John,
    thanks a lot for help!
    That would be the PSU for enclosures with power supplies for musical instruments, mostly analog synthesizers..
    Indeed, there are many on the market but loved to find a way to design one small and efficient and not too expensive.
    One TI member gave me advice of this solution:
    webench.ti.com/.../SDP.cgi
    but there in the BOM list there are some custom components that I don't know how to conceive.
    I hoped to find solution in webench, that the application calculate everything for me and make the pcb render but I realize that this functions easy only for some simple power solutions.
    There's a diagram for LM2587 typical use where there are all three Vout are presents +12,-12 and 5V but with 0.3A output
    www.ti.com/.../LM2587
    Don't know how to modify to obtain at least 0.9A

    Best regards
    Jovan
  • Yes that circuit would appear to work, but it does require a custom transformer. The specifications are included so you could use them to order a custom transformer. Probably there would be a minimum number to order though.

    The LM2587 is used in isolated flyback designs. This particular forum that I support is for non isolated designs, and my group specifically supports only buck (step down) converters. I would suggest you post your question about modifying that LM2587 design to the ac/dc and isolated dc/dc converter forum.
    e2e.ti.com/.../