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UC2843: Multi output flyback design

Part Number: UC2843

Hello everyone ; 

I want to design a flyback converter with input 10-18v DC and  isolated outputs  +6v 200mA , -6V 200mA and 4.3 with 250mA .  I could not find any application note to help in in calculation for multi  output. also webench dont support multi output . 

Could you help me in design or guide me to application or technical paper for the correct calculation ? 

Thank you in advanced 

  • Hi,

    A typical design procedure for multiple outputs is design with single output first. The single output is the output you would make feedback loop. After you decide this output then make it with your total power on this output. Then do the design with this single output.

    After you done with this single output design, then design your transformer with its secondary side windings to separate into your three outputs. Then decide each output secondary side circuit components.

  • Thank you for reply ; 

    when I calculate as single output ,what should be my output voltage ? for example -5v and +5v ? should I calculate as total 10V?  or seprare two 5volts ? 

    also what kind of  transformer is prefered , stacked ? or seperated winding ? 

    Regards 

  • Hi,

    Basically, you can use any since this is mainly to help to design the primary side. After you complete the primary side design, you will design your secondary side by transformer secondary side windings. You can do stack up or separated windings, depending on your applications. For example, if you need each output isolated to each other then you would have to use separated windings.