NgSpice Simulation Errors with linear regulator

[saramell]

Drawn in KICAD 8, this circuit is planned to provide a 3.6V (maximum current of 1.2A) by V2 before reaching to linear regulator to level down the voltage to 3.3V.
I expect the voltage out of the battery have a gradual growth from zero to 3.6V in nodes n1 and n2 . as well as the current across the capactiors to ultimately get a 3.3V output of the MCP1700.

My problem is that while I don’t get any particular errors by ERC (Electrical Rules Checker), I don’t get anything like what I expect to see in simulation. Can anyone spot problems with this circuit? or initial conditions? or even time values?

Thank you.

[Piotr]

Pin 1 of U1 is connected with nothing.
V2 ‘-’ pin is connected to the rest of circuit only by capacitors - you will certainly not get any DC current from it.
If you expect 1.2A flowing through 1k resistor than you assume voltage drop of 1200V at this resistor.

[saramell]

Thank you for your comment.
Do you recommend any connection other than GND for Pin 1 of U1? Do you also have any recommendation for V2 connection other than through circuit? I will also lower down the resistor value as you mentioned.
Thank you again for your help.

[Piotr]

@saramell

Do you recommend any connection other than GND for Pin 1 of U1?

Do you understand that if something is connected to GND and nothing else is connected to GND than this something is connected with nothing because GND is only a name of net and not gives automagically any connection?

[saramell]

I understand it but because I was following the data sheet of the LDO I’m using MCP1700-3302 then this configuration happened which obviously not working that’s why I’m asking for your help.

[jmk]

What @Piotr is subtly pointing out is the only part of your circuit that is grounded in the IC. The rest of the circuit needs a ground. Maybe the bottom of V2?

[saramell]

awesome, thank you. Do you think this updated version looks better? I didn’t get any ERC error regarding V2, but what can I do for the GND connection of C2, MCP1700, and C3?

[jmk]

Why not join all the gnds together?

Something like this arrangement (with your additional symbols) is a lot clearer.

[saramell]

Awesome, thank you. I created the circuit you propose, but still have the error for GND connection, can you point me to a probable issue? Thank you for your help

[jmk]

The warning should have a message in the dialogue box. What does that message read?

[saramell]

I changed it abit again but still get the same error - “Input power pin not driven by any output power pins”.

[Piotr]

You probably missed:

Getting Started in KiCad | 8.0 | English | Documentation | KiCad

[saramell]

Thank you, I read it through. Apparently as long as the simulation makes sense the errors can be igonored. cheers.