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TPS40210：TPS40210

w w2
Prodigy 90 points
Part Number: TPS40210

When TPS40210DGQ works in boost's topological mode, what are the risks when input equals output?

  • 0
    TI__Mastermind 31185 points

    Hi,

    Thanks for considering the usage of the TPS40210.

    There are 3 cases we can consider.

    In a boost configuration: 

    When there is no load, you can set the input equal to the output and there is no problem.

    When there is a short, current will pass from the input to output through the inductor and diode and damage the parts.

    If you load the circuit, it is impossible to force the input equal to the output due to the IR drop from the inductor and forward voltage of diode.

    Finally, if you set the input voltage to be very close to the output voltage, but still lower, you may also violate the minimum on-time specification of the TPS40210, which may cause it to skip a pulse or do other erratic behavior.

    I would recommend to make sure that your design does not violate the minimum on-time specification/maximum duty-cycle specifications of the IC.

    Thanks,

    Richard

  • 0 in reply to Richard Fu22
    Prodigy 90 points

    Thank you very much for your answer. I would like to ask another question. TPS40210 works in a boost configuration. When short circuit occurs, the current will be transmitted from the input to the output through inductors and diodes, which will damage the parts. How can this be avoided? TPS40210 does not seem to protect against this hazard.

  • 0 in reply to w w2
    TI__Mastermind 31185 points

    Hi,

    You can avoid damage by adding an external switch circuit, such as an NMOS transistor in series with the input power supply and boost converter, that will turn on when the short circuit condition occurs and disconnect the input until it is removed. 

    However, with adding an NMOS transistor, you will need a way to bias it. You can also use load switch ICs. You can look at those here: ti.com/power-management/power-switches/load-switches/overview.html

    Thanks,

    Richard

  • 0 in reply to Richard Fu22
    Prodigy 90 points

    Thank you so much for your answer.