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LM5150RUMEVM: Can I get a peak current for 4 amps at the output only for a few milliseconds?

Mehdi J
Prodigy 60 points
Part Number: LM5150RUMEVM

Hello, I want to know, if the Board can provide a peak current of 4 amp only for 10 ms, then a 2.5 ampere working current.

The datasheet of the LM5150RUM Evaluation Board shows the maximum current 2.95 ampere. If not do you have any alternatives ?

I need the boost converter for a small motor.

Motor specification:

Voltage : 8.5 V
Working current:  2.5A
Motor peak current at the beginning: 4A for 10 ms.

  • 0
    TI__Mastermind 48861 points
    HI

    Thermally, there is no problem to handle 4A for 10ms.
    Electrically, you should change some component values (especially Inductor, current sense resistor and compensation component values) to make the board work for 4.5A peak without current limited.
    Please download LM5150 quick start from www.ti.com/.../snvc214 and input your electrical requirements.

    Regards,
    EL
  • 0 in reply to EricLee
    Prodigy 60 points
    HI EL

    Thanks for your help. The excel file was really helpful.
    I have another question: My voltage source is a 4.2 V lithium cell. So I can not feed the LM5150RUMEVM with the 6 V start-up voltage at the beginning, I can feed only 4.2V.
    What should I change in the circuit to reduce the Start-up voltage value?

    Regards,
    Mehdi
  • 0 in reply to Mehdi J
    TI__Mastermind 48861 points

    Hi

    I spent a few days to think about it, but it seems there is no solution now.

    After initial start-up LM5150 supports down to 1.5V, but the device need at least 4.5V at VCC (or 5.0V at VOUT) to start-up initially.

    If you have another power rail which is greater than 5V, you may use a diode to supply LM5150's VOUT pin.

    Regards,

    EL