TPS61221的EN控制问题

确实输出电压会一直存在除非你把输入电压拿掉，因为内部MOS的二极管会导致输出一直有电。

说实话我也没见过这种类型的，EN不使能但是输入还在，就还有输出的；确实不常见。你可以在电源输入增加个MOS开关或者换型号。

Hi

   升压芯片很多都存在即便EN不启动，电路上仍然存在输出，电感，体二极管到输出的通路，所以en启动芯片正常升压，不启动不升压，但是有输出为输入减去体二极管压降。

   如果你希望输出没有电压，需要选择有隔断功能的升压芯片（很多的），当芯片不启动时，芯片内部是背靠背的肖特基，就不存在体二极管电流流向输出的问题。

TPS61221上是这么写的：
10.3.2 Device Enable And Shutdown Mode
The device is enabled when EN is driven high, and shut down when EN is low. During shutdown, the converter
stops switching and all internal control circuitry is turned off. During shutdown, the input voltage is connected to
the output through the back-gate diode of the rectifying MOSFET. This means that voltage is always present at
the output, which can be as high as the input voltage or lower depending on the load.

选择了TPS61097A应该可以吧：
8.3.2 Device Enable and Shutdown Mode
The device is enabled when EN is set high and shut down when EN is low. During shutdown, the converter stops
switching and all internal control circuitry is turned off.