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I'm doing a project with a Silicon Photo-multiplayer where the breakdown voltage when negatively biased is -25V. I was wondering is there anyway to connect two DC to DC boost converters to give me a virtual ground and positive and negative rails. I was looking at converters such as these.

I have access to a dual power supply but for reasons of portability it is not suitable. Thanks.

A

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  • \$\begingroup\$ Since most power supplies can only supply current but not sink current, such virtual ground set up usually does not work unless the negative rail always draws more current than the positive rail. \$\endgroup\$
    – rioraxe
    Commented Jan 23, 2017 at 1:01

2 Answers 2

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You can boost to +25V and +50V, then use +25V as a virtual ground. But why not buck-boost to -25V? Almost any normal buck would do the job.

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If you are powering both boost converters from the same power supply or from non-isolated supplies, then it will not work. The input and output ground is the same if the converter does not specify that it has a floating ground or "isolated output".

You are proposing to tie the output of one converter to the ground of the other converter. But the grounds are all the same so you are shorting the output of the converter intended as the negative supply.

Draw a diagram and it will become clear. Or I can draw a diagram if you want.

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