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Hey there,

first post from an avid forum reader:

This is the schematic for a simple Charge Pump circuit from circuitdigest.com* (great website). I am trying to build a charge pump with 12V VCC and 5V PWM, effectively giving ~17V at the output. I understand the working principle discussed on the website, though when building a "single stage" charge pump as shown above, does the PWM input need to be tied to GND? I get what all other components do.

My question is, does anything change when I disconnect PWN from GND? (doesn't otherwise get the pulses discharged directly into ground?) Im my design the pulse generator with be tied to the same ground as the OUTPUT GND.

Thank you very much!

Sources: *https://circuitdigest.com/electronic-circuits/charge-pump-circuit-design

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  • \$\begingroup\$ I’m voting to close this question because the first comment in the linked article tells you there is a problem with the circuit. Always read comments: You have a mistake in one of your circuit diagrams - the one where you add the peak detector. In that diagram, you show the PWM connected to ground. This probably wouldn't work! Oops! \$\endgroup\$
    – Andy aka
    Mar 17, 2021 at 14:56
  • \$\begingroup\$ Thank you, I totally missed that. Looked up on the internet and some other site basically copied the entire article, redrawing the schematic with the same error. \$\endgroup\$
    – Attenbach
    Mar 17, 2021 at 15:15
  • \$\begingroup\$ PWM signal source should drive only the bottom-end of C23. Be aware that your signal source should be of a type that can pull active "HI" as well as active "LOW":..current is pulled on one-half cycle, and pushed on the other half-cycle. \$\endgroup\$
    – glen_geek
    Mar 17, 2021 at 17:51

1 Answer 1

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If PWM is directly tied to GND, the circuit will not work.

PWM must be disconnected from GND.

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