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Electronics => Power/Renewable Energy/EV's => Topic started by: Sariel on October 28, 2024, 04:24:14 pm

Title: Charge pump for inverting a negative power supply
Post by: Sariel on October 28, 2024, 04:24:14 pm

Hello,

Can I use a standard off-the-shelf inverting charge pump (from TI or AD) to convert a negative power supply input into a positive voltage?

Are there any specific precautions I should consider? Can I connect the charge pump in the same way as in its typical application?

Thanks!

Title: Re: Charge pump for inverting a negative power supply
Post by: PCB.Wiz on October 30, 2024, 04:02:02 am

You did not mention what voltage and current ?
You need a charge pump that can start-up, which means the switching section needs to work initially on the supplies you have available.

Inverting charge pumps (like 7660) used for voltage doubling examples usually have 2 diodes externally.

eg A Charge pump designed for doubling, like LM7665 can double 0,5V to 10V, or can be connected 0V, -5V to 'double' that to +5V


 

Title: Re: Charge pump for inverting a negative power supply
Post by: nctnico on October 30, 2024, 02:11:46 pm

Quote from: Sariel on October 28, 2024, 04:24:14 pm

Hello,

Can I use a standard off-the-shelf inverting charge pump (from TI or AD) to convert a negative power supply input into a positive voltage?

Are there any specific precautions I should consider? Can I connect the charge pump in the same way as in its typical application?

The only thing to be aware of is that charge pumps tend to be noisy. Some have linear post-regulators to clean up the output voltage but even then the charge pump itself can be a source of noise.