Simple negative power supply (-5V / -12V / -15V)

Sometimes you need a simple negative power supply. The best example is the contrast PSU for common small LCD device. Building -5V from a battery or a wallmart supply isn’t really easy. I decided to build a small device that is able to provide -5V, -12V, -15V. I used the MAX 764/765/766 serie. Simply change the chip to provide the good output.

Here the little schematic:

And here a pic, of the result:

As you can see, this stuff is damm small, use some common parts and can be reuse across different needs. Thanks Maxim for the sample :)

I used a 220uF instead of the 120uF one, and a small inductor but you can use a bigger one, if you need greater current.

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6 thoughts on “Simple negative power supply (-5V / -12V / -15V)

  1. Low-power negative supplies are good for -Vcc for audio preamps or any other opamp circuit for that matter.

  2. Did you also create a matching +15v power supply? If so, what did you use?

  3. —Can a -12v be used in place of a -5v? I need to replace the power supply for my MS-9620 (K8N Master2-FAR) which requires a -5V and I have a power supply with -12V.

  4. Can you please tell me which inductor you choose?
    I’m searching for a small SMD(if possible) inductor.
    The inductors described in the datasheet are relative big..

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