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Suggest me a control chip or design for a DC-DC buck converter for 10A output

MD MUBDIUL HASAN
Intellectual 780 points
Other Parts Discussed in Thread: LM5145, LM5143

Hi,

Suggest me a control chip or design for a DC-DC buck converter.
Here is the specification.

1. Maximum input voltage=48 V
2. Minimum input voltage=36V
3. Nominal output voltage = 12 (plus minus 5%)
4. Maximum output current=10A
5. Operating temerature = -40 to 80
6. OVR protection
7.OCR protection
8. "ENABLE" Signal
9. "FAULT" signal
10. LED indication.

Hope you will help me.
Hasan

  • 0
    TI__Mastermind 27470 points

    HI

    I will recommend LM5145

    see below link:

    www.ti.com/.../lm5145

  • 0 in reply to Daniel Li14
    Intellectual 780 points

    Daniel,

    Thank you. Good datasheet indeed. Make sure that its applicable for 10A.

    It might have parameter design Exel sheet.

    Let me put few questions that you know better.

    +85 deg C at full power is a big ask - do you really OK with this ?

    -40 deg C is a big ask too - you really need expensive electro's and quality SMT caps to perform over this range.

    Will the input voltage ever go over 48VDC? even at hard switch on ? - this needs considering..!

    How about radiated RF noise and conducted noise down the input & output wires (?) does this factor in ?

    What is the output ripple to be 250mV rms ? the input current ripple, 500mA rms ?

    Obviously a buck converter will work - 2 phase would be better here, only 5A chokes, and reduced input current ripple.

    What is the dynamic performance required on the output - for load steps ?

     There is a lot to go wrong here and it is easy to overlook things

    for e.g. in a +85 ambient - all the parts will be sitting at 100 deg C or hotter - so the parts had better be pretty good.

  • 0 in reply to MD MUBDIUL HASAN
    TI__Mastermind 27470 points

    HI

    the buck controller design is related the frequency, moseft, inductor chosen. So we provide a excel tools for efficiency calculation. i

    https://www.ti.com/lit/zip/snvc206?_ticdt=MTY1ODg0MTQzMnwwMTc4MTQ1OGZhZDkwMGNkODMzYzNkNzZkNWM4MDMwNzMwMDEzMDZiMDBiZDB8R0ExLjMuMTE0NzI4MTAxMS4xNTc5NDQ1OTgyfDA

    If proper device and good thermal dissipation way used, it will be possible working at 85deg C. and you can also get the  input and output ripple from the tools.

    if you need 2Phase design, you can choose LM5143.  I suggest you can use Pspice model to simulated the transient as it is related to the loop setup and output capacitance.

    for RE and CE, we don't know the result as it not only related to PCB layout but also related to you input filter design. 

    Thanks