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Original question:

WEBENCH® Tools/TPS55340: To use one step or two step boost from 3.3V input boost to 24V output

WEBENCH® Tools/TPS55340: To use one step or two step boost from 3.3V input boost to 24V output

Jin Jiang
Intellectual 310 points
Part Number: TPS55340
Other Parts Discussed in Thread: TPS43061, LM5122

Tool/software: WEBENCH® Design Tools

Dear Sir/Madam,

As TPS55340 can only achieve 85% efficiency when boosting from 3.3V to 24V at 0.5A, is there other boost converter that can give me 95% efficiency? Realistically, what is the maximum efficiency I can get when boosting from 3.3V to 24V.

Thanks.

Jin

  • 0
    TI__Intellectual 2655 points
    Hi Jin,
    On your working condition, it is hard for boost converter to get 95% efficiency. I suggest you could use synchronous boost controller.
  • 0
    TI__Mastermind 40080 points

    Hi Jin,

    Suggest you use TPS43061, this is a Synchronous Boost controller which can achieve >90% efficiency.  The IC's Vin pin should be supplied by a separate 5V voltage when the power Vin is lower than 4.8V.

  • 0 in reply to Helen chen
    Intellectual 310 points
    Helen,
    Thank you for the assessment and recommendation. I used LM5122 in one of our previous design. It has the similar requirement of supplying a voltage of 4.5V plus when the main Vin can be as low as 3V. This will add complexity to the circuit. But if it is the cost to get a higher overall efficiency of >90%, I will do it. Is there any white paper describing the reason behind that a voltage of 5V needed? Or it is a general rule that from Vin=3V to Vout=24V, it is too high for one boost converter to handle when the output current is at less than 1A range?
    Thanks.
    Jin
  • 0 in reply to Jin Jiang
    TI__Mastermind 40080 points

    Hi Jin,

    Need an extra 5V is because TPS43061 has minimum startup voltage requirement and UVL requirement. Please check the below table: