Can't simulate charge pump.

Hello! I'm pretty new to electronics and circuit simulations. Trying to implement a basic charge pump using tutorials in internet. But it simply doesn't work. I tried to use circuits from multiple tutorials, tried to think myself, eventually I'm simply not sure whether I'm doing something wrong or it's a simulation issue.

by inarkin
October 11, 2023

Not sure what your goal is. Try a simulation on time domain, start 0, end 0.5m, step 0.1u, output pwmout and loadup. Seems fine.

by vanderghast
October 11, 2023

I expect to have 20v in loadup and i see 50mV

by inarkin
October 18, 2023

R5 is way too small. $${20 V / 2 \Omega}$$ implies 10 A.

10A times 20 V implies 200 Watt !

Your 4V battery would have to supply not less than those 200 W, or ... not less than 50 A ! (For conservation of energy, at 4 Volt.)

Change R5 from 2 to 200K and you will see the pump in action.

by vanderghast
October 18, 2023

Interesting. Now I see. But in real life the circuit it's gonna be connected to a bank of 18650 batteries which actually can supply 120A current together.

by inarkin
October 18, 2023

Note that with 120 A, even an internal resistance of 10 milli ohm (which is not even reached at a so low value with most MOSFET), that pumps OUT of the system 1.2 volt. If 10 milli ohm is the internal resistance of the battery (including connection), passing through 4 of them, in series, that is 5 Volt lost, just there.

by vanderghast
October 19, 2023

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