BQ4050 短路功能

GR ling

Prodigy 110 points

Other Parts Discussed in Thread: BQ4050

在测试BQ4050短路的时候，出现了如下情况：

当电池包静止一段时间（使电池包进入睡眠状态），这个时候做直接短路测试，发现短路会出现短暂恢复的情况。

如果接上通讯来测试，则没有这种情况，短路保护后不会恢复。

请问有什么相关设置改善这种情况？

5 年多前

0 Star Xu 5 年多前

TI__Guru*** 130456 points

看一下参数DA Configuration[SLEEPCHG]是否设置，将这个bit置0，确保sleep mode 时CHG FET, DSG FET, PCHG FET都是关的

0 GR ling 5 年多前回复 Star Xu

Prodigy 110 points

但是我们的应用不能在睡眠的时候关闭放电管。

请问这种现象是参数配置出错了，还是这个芯片本来就有这种缺陷，或是硬件设计的问题？

谢谢。

0 Star Xu 5 年多前回复 GR ling

TI__Guru*** 130456 points

您方便抓个波形看一下吗？

0 GR ling 5 年多前回复 Star Xu

Prodigy 110 points

睡眠状态下测试，如下图

在正常状态下测试的波形

0 Star Xu 5 年多前回复 GR ling

TI__Guru*** 130456 points

Yes the behavior is normal based on the recovery time. Then the DSG FET turns off the short circuit current drops to 0 then the fault clears and the DSG FET turns ON, since the short circuit condition is still present it will cause the DSG FET to turn OFF again. The DSG FET will continue to toggle ON and OFF. There's a way to make the DSG FET latch OFF after toggling a number of times ASCDL. For OCD it can be latched by setting the recovery current threshold positive, which would require a charger current to recovery from the condition.

0 GR ling 5 年多前回复 Star Xu

Prodigy 110 points

Thank you Star.

But the time grid of the waveforms is 2ms, the recovery delay we set is 60s, I don't think it recovers normally.

Based on the settings, the expected behavior is, DSG FET turns off when short occur, after 60s, if the short circuit condition is still present, DSG FET turns off again, until 5 times, the DSG GET is latched off. Am I right?

While known form the pic I posted, DSG FET recovers in about 6ms after short protection. Is it possible that the firmware turns on DSG FET by mistake when exitting sleep mode?

Thanks.