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Can we build a capacitor stack up in voltage by switching a capacitor?

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opampsmoker

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Hi,
Can we do the attached...ie , build up a capacitor stack in voltage up to 9V from a 3V battery?

I kind of thought that there is some danger of causing ESD damage to the ADG1438 multiplexor in the process?.....ie the capacitor leads could get induced up to high voltage somehow and then cause ESD damage when the ADG1438 switches?
 

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This has nothing to do with ESD.

But you are switching HUGE capacitance with nothing to limit current other than the switch resistance; I'd be concerned. Peak current for the device is 400mA. What does your LTSPICE simulation show for currents? Also, try replacing the wires with small inductances and see what happens to your currents and voltages.
 
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I experimented with many simulations trying to make a 3-capacitor stack into a voltage tripler. (My aim is to do this from a single 1.5V battery.)
The caps must be charged singly in rotation. It requires 3 half-bridges activated by clocking signals which are difficult to get right.

Bare schematic:

bare schematic 3 caps stacked 3 PNP 3 NPN.png


The middle capacitor tends to find opportunities to discharge through neighboring half-bridges as polarities change at different nodes.

This isn't to say it's impossible to make it work.

We might consider alternate methods:
* Nakagome topology
* Dickson topology
* First a voltage doubler, used to power a second voltage doubler.
 
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So your putting the caps in series to get an increase in volts right, This circuit is possible, ive done it before, and ive tested it, but only with 4 capacitors, and it went from 7 volts to about 9, because my circuit was a bit lossy.
I dont think the simulations on the internet are any good, I disagree with their behaviour.
 
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