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  • TI Thinks Resolved

TPS61021A: peak current issue

Part Number: TPS61021A

Hi all:

      In my design, i want to use a Lithium-Manganese battery(voltage range is form 1.5v-3v) as a power source for a dcdc boost power ic, and i will use the dcdc boost power ic  to driver a gsm RF module, due to the work mode of gsm system, the RF module need 3.8v input, and the peak current of this module is about 2A(the peak current continued time is abour 5us), so , i searched in TI's website and i find the tps61021a has the similar performance, but i am afraid whether tps61021a could afford the peak current of the gsm RF module?i want to know which power ic i can choice?

Thanks.

  • Since the 2A peak current only lasts 5us, so TPS61021A is still oK for the applicaiton if you put a big capacitance at the output side. a 10-22uF ceramic cap plus a 220uF-470uF EL cap can be added at the output side.

    Best Regards,
    Helen

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  • In reply to Helen chen:

    Sorry,i made a mistake, i measued the peak current, it is about 2.4A, and it lasts about 580us, the output volage drop of the TPS61021A is about 0.7V, so, is this ok?

  • In reply to Matthew.huang:

    What is the output capacitance you used? with a bigger capacitance, the voltage can be smaller.

    Best Regards,
    Helen

    Boost DC/DC Solution

  • In reply to Helen chen:

    Hi Helen:

    I add two 220uF tantalum output capacitors and the output voltage drop goes well.
    But the spec suggest that the output capacitor should be smaller than 200uF(you can see it in the picture below).
    So, could i add two 220uF tantalum capacitors?
    Thanks.

  • In reply to Matthew.huang:

    this remark is considering all the input voltage range. In your input voltage range, two pcs 220uF cap is OK. But make sure Vin should be >2V. Or it can't support 3.8V/2.4A peak current.

    Best Regards,
    Helen

    Boost DC/DC Solution

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