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PMP10725: Transformer

Sarumathi R
Intellectual 480 points
Part Number: PMP10725
Other Parts Discussed in Thread: LM3481

Hi,

We need 5 isolated output as below,

Output Voltage 1 24VDC/200mA
Output Voltage 2 24VDC/150mA
Output Voltage 3 24VDC/160mA
Output Voltage 4 24VDC/250mA
Output Voltage 5 24VDC/140mA

In PMP10725, there are 3 isolated output(24V, 16V and 16V)

Our input voltage:24VDC.

Can I use this reference design if I change transformer with 5 outputs.

Will it work?

Guide me with some suggestions.

  • 0
    TI__Intellectual 2770 points

    Hello Sir,

    PMP10725 uses controller LM3481 plus external FET,
    so you are not limited by any internal current limitation.
    So this will work for your application 20W..30W.

    Please use Power Stage Designer to analyze primary currents,
    to figure out best windings ratio etc.

    Best regards, bernd

  • 0 in reply to Bernd Geck
    Intellectual 480 points

    Hi,

    I have one more doubt.

    PMP10725 have two variant one is primary side control and another one is secondary side control.

    For our output requirement(which I shared already), which is one preferable?

    Kindly give me some suggestion on that.

  • 0 in reply to Sarumathi R
    TI__Intellectual 2770 points

    Hello Sir,

    if you go for primary side regulation PSR you could avoid the opto isolator,
    but you have to allow more tolerance at load regulation.
    Using PSR needs best coupling in between auxiliary and secondary winding.

    Best regards, Bernd

  • 0 in reply to Bernd Geck
    Intellectual 480 points

    Hi,

    Input voltage 24VDC
    Output Voltage 1 24VDC/1200mA
    Output Voltage 2 24VDC/250mA
    Output Voltage 3 24VDC/250mA

    If this is our power requirement, the output power will go around 36W.

    Shall I follow PMP10725?

  • 0 in reply to Sarumathi R
    TI__Intellectual 2770 points

    Hello Sir,

    PMP10725 could be a very first starting point, but your specification is totally different:
    your bigger power requirements are needing a stronger power stage;
    for 36W I would run this power stage in CCM;
    your output voltages are different, so transformer needs a different windings ratio 1:1:1:1;
    this will result in good coupling and PSR is a reasonable option.
    Loop needs to be adjusted to the new power stage, CS resistor needs to be lowered.

    So PMP10725 needs rework to modify it to your needs,
    please use Power Stage Designer and follow the data sheet, best regards, Bernd