Looking for 24V to 48V conversion for phantom power

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This is a board made from that schematic. It needs a little tweaking as the output is 45V and not 48V. Not really an issue but for sake of being exact it could stand to use a little adjustment.

Thanks!

Paul
 

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45V is technically in-spec for P48 phantom power, which is 48V +/- 4V (44-52V) delivered through 6k8 resistors.
That is why I said 45V is not really an issue. Some mics will operate with voltages as low as 10V. The desire to be at 48V is to satisfy the OCD in myself and others who suffer from needing things to be exact.

Thanks!

Paul
 
Keep in mind I haven't actually used that, I just found it based on some vendors I knew had products that might work.
I feel your pain on the power supply problem, there are a few switching devices that might work, but some would require winding a custom transformer, which is a big learning curve for a one-off project. Others might be able to use off-the-shelf inductors but still are a lot of layout work to get quiet (electrically) for audio use.

One thing I noticed looking over the datasheet for that charge pump is that it seems to change switching frequency based on load, which can sometimes cause a problem with audio. If you have additional filtering on the output, when the switching frequency decreases the ripple frequency might move below your filter cutoff, so a supply that was quiet enough with multiple loads might get noisier with lighter loads.
Look through the datasheet and see if there is a fixed frequency mode you can force, or if that is not possible make sure you look at the lowest and highest switching frequencies it will use and size your output filter appropriately.
Have you explored the Versa-Pac products?
https://www.eaton.com/content/dam/e...rsa-pac-inductors-transformers-data-sheet.pdf
 
I was using a DC/DC converter from MURATA or Recom which works well for 4 Channels. The 2424S converter was about 7€.
The components on the left side of the schematic are a general noise filter for the 24 supply.
 

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I was using a DC/DC converter from MURATA or Recom which works well for 4 Channels. The 2424S converter was about 7€.
The components on the left side of the schematic are a general noise filter for the 24 supply.
Yes, that is one of the best solutions. Considering the usage of an NPN voltage follower configured as capacitance multiplier should reduce all noise components to safe levels...
 

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