Choosing the correct Dc to DC topology

Discussion in 'General Electronics Chat' started by jegan, Jul 25, 2007.

  1. jegan

    Thread Starter New Member

    Jul 25, 2007
    hello all...

    I'm new here.I have been asked to design a SMPS with 300W "25V" output power, with a good transient response,low EMI,good load and line regulation and improved efficiency.

    So, can any one guide me or suggest the best DC-DC topology the i can use for the above requirements.

    It would be a great pleasure if anyone could reply me.

    Thank You.
  2. Papabravo


    Feb 24, 2006
    Let us start with the available input voltage and power. The input power will need to be 375 watts at 80% efficiency. Your output is 25V @ 12 Amps. You are going to need some heavy duty inductors for those kind of currents. You may need to research core materials and wind your own. If the input voltage is lower than the output voltage you will need a boost converter. If the input voltage is greater than the output voltage you will need a buck converter. If the input voltage range surrounds the output voltage then a SEPIC converter.

    There are some other design possibilities but those should get you started. Have you ever designed one before? What resources has your company offered you to help in this task? This seems like a challenging project for a fresh out or even an experienced hand.
  3. John Luciani

    AAC Fanatic!

    Apr 3, 2007
    Other than output power you have no quantified any specifications. You need
    to start with a specification.

    It probably makes more sense to purchase a converter. Check out

    (* jcl *)
  4. jegan

    Thread Starter New Member

    Jul 25, 2007

    Dear Sir,

    Thank You very much for the reply.ok now the input voltage would be from a AC supply and rectified to high DC supply. This high DC supply will be the input for the DC-DC converter. Since the company wants me to design a SMPS which gives an output of 300W ''25V''..So i have done a literature review based and from my review it says that push pull converter, half bridge converter of full bridge converter would be able to give a high output power..i am concentrating to Isolation circuitry, Buck or buck boost is a non- isolated circuitry. So im a little bit confused on which topology would be the best in order to meet the requirements of my company in order to design the SMPS