Which transistor-controlled MOS tube switch circuit is better?

Knight97538

Which transistor-controlled MOS tube switch circuit is better? [Copy link]

Which of the following control circuits is better?
The MOS tube is turned on with 12V, and the 51 microcontroller is powered by 5V. I am not sure which of the following two control circuits is better. Please explain the analysis and reasons. Thank you.

dcexpert

Why use a 12V MOS to control it? Wouldn't it be simpler to use a low voltage one and a single power supply?

maychang

Figure 2 is likely to be "unable to turn off", that is, the MOS tube is turned off for a long time (possibly several seconds or longer) after the +5V disappears.

秦天qintian0303

Where is your output?

bigbat

Figure 1 is better. As mentioned in the second post, Figure 2 may not be able to shut down, and because the GS impedance is very high, it may cause false operation.

jimtien

The second picture is wrong, the transistors cannot work

chunyang

The picture below is wrong, and the picture above is a shooter follower, which is also wrong.