Of course, I could introduce the scheme into LTspice, but it is pleasant and convenient for me to work with Qspice. This is a new simulator and it has improved transistor models. There is quite a lot of continuity with LTspice. The scheme is simple and you can enter it into any simulator.
You can also install Qspice. It is free and has no limit on the size of the circuit. You can borrow my model libraries. I have made a large library of models for LTspice. There are links to them on this forum. Now I'm busy replenishing the library for Qspice. I post them on the forum kazus.ru . There I made a Qspice theme. There are models and many electrical circuits in it.

I installed the QSPICE, opened your file and run it. But I got a black empty window. How can I run the simulation properly?

Raw file shows:
M1 N01 N03 N02 N02 2N7002 NMOS
R1 N01 N05 300K
M2 N04 N01 ADC ADC 2N7002 NMOS
R2 N04 N05 15K
R3 0 ADC 1K
V´U1 N05 0 16V
Ą1 N03 0 N02 Ą cntr Ą Ą Ą Ą Ą Ą Ą Ą Ą Ą Ą OR
V1 N03 0 3.3V
V2 cntr 0 PULSE 0 3.3 100m 10n 10n 200m 500m
C1 ADC 0 10n
.tran 400m
.lib "C:\Program Files\QSPICE\NMOS.txt"
.end

 

I installed the QSPICE, opened your file and run it. But I got a black empty window. How can I run the simulation properly?

Right-click on the graphics diagram (I changed the background to white), a menu will appear, add Plot. Select what you want to display in the graph field. I'm sorry, I should have written on the diagram:
.Plot v(cntr) v(adc)
To enter text, press the letter T and then type.

 

Right-click on the graphics diagram (I changed the background to white), a menu will appear, add Plot. Select what you want to display in the graph field. I'm sorry, I should have written on the diagram:
.Plot v(cntr) v(adc)
To enter text, press the letter T and then type.

Thank you for your advice, it shows the chart now.

I need to use as few components as possible, so thanks to the advice of Texas Instruments I preferred to use the TPS22810 power switch. Simulation in Tina-TI.

 

You are giving a strange enabling signal.

 

You are giving a strange enabling signal.
View attachment 333194

Perfect ;-). I overlooked that the generated square wave signal is bipolar. I corrected it by adding an offset of 1.65V and signal amplitude of 1.65V.