Cheap DC-DC LM2596 Module for negative rail

[jadew]

Hello,

So I got these LM2596 modules from ebay and by the look of the datasheet it appears that they can be used as inverting buck-boost.

The only difference I noticed in the datasheet (between normal and inverted) is the fact that the ground and the output become reversed.

I tried it, but it doesn't work, it just draws all the current it can draw from the supply.

Any thoughts?

Datasheet: http://www.onsemi.com/pub_link/Collateral/LM2596-D.PDF