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TPS55332-Q1: Boost regulator for 48V@1.7A

Devipriya S
Prodigy 30 points
Part Number: TPS55332-Q1
Other Parts Discussed in Thread: LM5158, LM5157, LM5155, LM5156

Tool/software:

Hello team,

We are planning to use boost regulator TPS55332-Q1 for below requirement of Automotive grade

Vin=12V, Vout=48V@1.7A

Could you please confirm will this boost works for our application as earliest.

Awaiting for your response.

Regards,

Devipriya



  • 0
    Prodigy 30 points

    By the way, I found an another alternate for same PoE PSE requirement for the above requirement, LM5158.
    But peak current limit margin is not supporting. Could you pleas suggest an better alternate for 4Pair PoE application.

    Regards,

    Devipriya

  • 0
    TI__Genius 17655 points

    Hello Devipriya,

    Thanks for reaching out to us via e2e.

    Let's do a quick rough calculation:
    When the output voltage is 4x the input voltage, the average input current will be 4x the load current.
    The peak current will be about 30% higher than the average current.
    Plus some adder for efficiency losses and component tolerances (maybe 20% overall).

    1.7 * 4 * 1.3 * 1.2 = 10.6A peak current for the (integrated) low side FET.

    The TPS55332-Q1 is rated at 5.7A, but also the newer LM5157 can only handle 7.5A as a maximum.

    So, I am afraid that none of our converters with integrated FET can handle the required current.

    Please have a look at our controllers with external FET instead, like e.g. the LM5155 / 56.

    Best regards
    Harry

  • 0 in reply to Harry Hofner
    Prodigy 30 points

    Thanks for your suggestions.

    We are planning to use LM5156 with external FET for our requirement.

    But the LM5156 is rated as catalog. Will it be suitable for automotive application?

    Please confirm.

    Regards,

    Devipriya

  • 0 in reply to Devipriya S
    TI__Genius 17655 points

    Hello Devipriya,

    The LM5156 is the industrial version of this device.

    For automotive applications, please use the Q1 variant:
    www.ti.com/.../LM5156-Q1

    Best regards
    Harry