This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ25505: 个人根据EVM设计BQ25505外围电路,设置VBAT_OV为4.5V,VBAT_OK_HYST为4.2V,但是实测的时候发现超级电容能够充电到4.5V,而VBAT_OK一直为低电平

Part Number: BQ25505


问题如上,实测的输入使用直流电源进行CV输入,并没有设置MMPT点和采样,发现芯片能够对超级电容进行充电,但是VBAT_OK一直为低电平不会升压,请问这是为什么?具体电路图如下(其中第二幅图没有设置采样点)

  • 您好,正在查询,稍后回复。

  • 您好,请参考下面的内容:

    OK_HYST=4.3V from one set of the resistors in the schematic. 

    The issue could be the parallel, parasitic ~ 1M resistor from solder flux as explained in datasheet section 10.  There are 2 ways to test:

    1. remove the resistors, clean off the flux and replace there resistors on their edge to minimize surface area for new parasitic resistor

    2. replace resistors with 1/3 - 1/10 the value