Hi Guys,

I want to connect Linear regulator ground via switch in negative rail as per below >
So i need two switch > 1. Push Button > 2. Active Switch(MOSFET)
The Idea was when user press the switch there is supply voltage between Vout and GND and once there is power supply builds up it enables microcontoller. Now microcontroller make path between Vout and GND. As long as microcontroller need power it enable the active switch otherwise it switch off the power supply.

I have done simulation but it is not working as expected.
Could anybody help me out here ?

 

You do realize that regardless of the status of Q1, the MOSFET gate will be grounded?

 

And I think if you lift the regulator ground it will give the maximum output voltage it can, not switch off.

 

You do realize that regardless of the status of Q1, the MOSFET gate will be grounded?

Thanks !
Yes , I realized but it is still not working.

 

And I think if you lift the regulator ground it will give the maximum output voltage it can, not switch off.

Thanks !

I do not know how it can be implemented. I tried with my idea.
Hope you have understand what i am trying to do ?

 

Hello All,

I still can not figure out why it is not working.
Could any one help me out here if this will work or not ?

Thanks In Advance !

 

I think you will need to put the MOSFET switch on the input or output from the regulator. Putting it on the input will also eliminate the quiescent regulator current when it is off.

 

I think you will need to put the MOSFET switch on the input or output from the regulator. Putting it on the input will also eliminate the quiescent regulator current when it is off.

Many thanks !
Could you please edit lt spice file and share me ?

 

AlbertHall is correct, if you lift the ground the max voltage will be present at Vcc and better to switch the supply voltage at the input.
Something like the schematic below. Component values dependent on your specs.
Steve G