BQ25710: boost mode transition to buck-boost mode, the switching have one buck and five boost pluses

Part Number: BQ25710


Hi, Ti guys
I have a confusion about the BQ25710 work behavior when from boost mode transition to buck-boost mode:
1. VBUS=10V, VSYS=12.4V, Vsys loading=2A, BQ25710 work in boost mode, when VBUS change from 10V to 12V,BQ25710 will enter from boost mode to buck-boost mode,  the waveform below shows that there is one buck pluse and five boost pluses, and the buck&boost pluse is not periodic with vbus voltage change,  I can't understant the actions, can you explain the principle? My understanding is that the switching pluse should is one buck pluse and one boost pluse alternately in buck-boost mode.

2. When VBUS change to 13V,  the switching pluse  is one buck pluse and one boost pluse alternately, this is correct.

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  • Hi,

    We have received your post and the investigation will take some time. Thank you for your patience.

  • 您好

    这是正常现象。当我们将降压操作转换为升压操作时,会进入降压-升压混合操作模式。如图示,您会看到降压减少而升压增多。

    在降压脉冲之间插入多个提升脉冲以实现平滑过渡,这对德州仪器(TI)而言是有利的。

    所有波形均正确!

  • Hi, Daniel:
    再问一下一个问题:

    1.当进入降压-升压混合模式后, 前一周期插入的是降压脉冲或升压脉冲,下一周期需要插入降压脉冲还是升压脉冲,这个判断条件是什么?

  • Hi, Daniel:
    1.当进入降压-升压混合模式后, 前一周期插入的是降压脉冲或升压脉冲,下一周期需要插入降压脉冲还是升压脉冲,这个判断条件是什么?
    2. 结合第1点,如下波形有的时候即不插入降压 脉冲,也不插入升压脉冲, 这个判断条件又是什么?

  • 您好

    这款芯片运行流畅无阻。VSYS纹波低,效率高。但我并未察觉对客户有任何影响。由于知识产权保护,我们无法讨论其内部电路或实现方式。