[sdiy] SSM2164 last time buys

[Scott Juskiw]

The problem I'm trying to solve is the lack of a negative supply when ground and positive supply are present. I'd like to have the positive supply be disconnected if the negative supply becomes disconnected. And, I suppose, the solution should also disconnect the negative supply if the positive supply is not present.

> I'm not sure the problem here is clearly defined.
> Is it a lack of a negative supply when the positive and ground rails are
> present ?
> Is it the presence of input voltages below the level of the absent negative
> rail ?