对于BQ24070,在CE接低电平的情况下,其内部Q1管是关闭的,Q2管是打开的。从它的内部结构看Q1是个PMOS,OUT脚到IN脚之间是用Q1直接连接的,虽然CE为低的时候Q1切断了IN到OUT的通路,但是从OUT到IN这个方向仍然是通的,也就是说,这个时候电池的电会通过Q2再经过Q1反灌到IN脚上??这样的话,如果不充电的情况下输入端口是带电的????????麻烦帮忙解答一下
Star Xu:
The CE (chip enable) digital input is used to disable or enable the IC. A high-level signal on this pin enables the chip, and a low-level signal disables the device and initiates the standby mode. The bq24070/1 enters the low-power standby mode when the CE input is low with input present. In this suspend mode, internal power FET Q1 (see block diagram) is turned off; the battery (BAT pin) is used to power the system via Q2 and the OUT pin. This feature is designed to limit the power drawn from the input supply (such as USB suspend mode).
user5725400:
回复 Star Xu:
这段话是在描述CE为低的时候,外部电源无法从输入pin进来,但是我的问题是电池的电是否会通过Q1反灌到输入pin,因为从结构图上看,很明显Q1是个Pmos,D极到S极始终是通的。请问能解答一下我的问题吗,而不是贴datasheet上来
user5725400:
回复 Star Xu:
能回答一下吗
Star Xu:
回复 user5725400:
When IN is present and the device is in normal operation, Q1 and Q2 will be on to allows for battery charging and power OUT. If VIN goes away or a short causes Q1 to turn off, the IN pin will not have the OUT voltage.