I'm designing an LDO with dual outputs (Vout and -Vout), and only the positive output is shown in the pictures below. I'm having large trouble using dual supply op-amps in the design, and my single-supply one works fine and is shown in the first image.
But my LDO using a dual-supply op-amp does not work at all in the same configuration, and I've tried a few different dual-rail op-amps. Am I missing something in the dual-supply design?
The design with a dual-supply op-amp just saturates to the positive rail.
The problem was that the dual supply could not get close enough to the rail.