Hi ,大家好:
现在基于类似于BBB的开发板,使用的电源管理芯片是TPS65217C,我想外接DC断电时内置3.7V锂电池工作继续供电。现在的问题是,外接电源断开,锂电池供电这个很正常,锂电池处于供电状态时,我想通过软件或硬件来控制芯片变为OFF 或SLLEP,可是不能实现。
1.首先我想通过拉低PB_IN 大于8s时间,发现开发板会不断重启,而不是sleep。当只有外部电源供电时(内置锂电池没有接),正常状态下拉低PB_IN会正常关机,这个是什么原因?
2.尝试拉低PB_IN不行,我想通过halt 或poweroff来关机,发现现象还是重启设备,不能正常关机。
Anfeng Qu:
1. 你检测下你的系统应该是进入如下这种情况了,因此再同时比较下你现在测试的两种情况下nRESET脚的电平情况,这块可能会有些影响
If the PB_IN pin is kept low for an extended amount of time, the device will continue to cycle between ACTIVE and RESET state, entering RESET every 8 s.
2. 要实现关机,如下方法都可以的啊!
A power-down sequence is executed if one of the following events occurs:
• The SEQDWN bit is set.• The PWR_EN pin is pulled low.• The push-button is pressed for > 8 s.• The nRESET pin is pulled low.• A fault occurs in the IC (OTS, UVLO, PGOOD failure).• The PWR_EN pin is not asserted (pulled high) within 5 seconds of a power-up event and the OFF bit is set to 1.