电源电压瞬态问题自动断电

大家好，我正在研究一个简单的电路与PIC12LF1501应该被激活的开关，保持自己的动力通过一个PMOS + NMOS对（PMOS器件绕过电源开关，NMOS驱动PMOS），并关闭自己关闭NIC晶体管通过PIC的RA5，这是主动驱动低。现在的问题是，当电源以这种方式关闭，端口RA5切换到H输出，一旦电源电压下降到约1伏-这就足以再次切换电源。这种情况总是发生，不管我如何配置RA5。我可能需要通过分频网络来驱动NMOS，将栅极电压降低到低于VTH @ 1伏特电源电压，但我想知道是否还有另一种解决方案（如果其他人遇到了同样的问题）。NMOS器件具有相当宽的VTH范围，在0.6到1.5伏特之间，这是复杂的，这只会带来3伏电源电压的问题。也许我最好在这里切换到一个NPN双极晶体管…谢谢你对这件事的任何想法！



      以下为原文

    Hi all,
I'm working on a simple circuit with a PIC12LF1501 that is supposed to be activated with a switch, keeping itself powered up via a PMOS+NMOS pair (the PMOS device bypassing the supply switch, NMOS to drive the PMOS), and switch itself off by turning off the NMOS transistor through the PIC's RA5, which is actively driven low.

The problem now is that when the power is switched off in this manner, port RA5 switches to a H output as soon as the supply voltage drops to approximately 1 volt -- and this is enough to switch the power back on again. This always happens, regardless how I configure RA5.

I probably need to drive the NMOS via a divider network to lower the gate voltage to below Vth @ 1 volt supply voltage, but I wondered if there is another solution to this (and if other people experienced the same problem). It is also complicating that the NMOS device has a rather wide Vth range, between 0.6 and 1.5 volts -- which presents a bit of a problem with only 3 volts supply voltage. Perhaps I'd better switch to an NPN bipolar transistor here ...

Thanks in advance for any thoughts on this matter!