Voltage regulators - die pictures

[magic]

Maybe slightly better

But WTF is this circuit here? I gather the first MOSFET pair is a P-ch current mirror (gate shorted to "southern" drain) and the next is an N-ch differential pair, and they drive the output FET directly. Pretty obvious so far.

The rest must be the voltage reference, and what exactly happens here? Looks like the current source from the simplified schematic is a series pair of N-MOS with gates shorted to sources (or floating?), and the "resistor" is a diode connected(?) N-MOS. And this is supposed to produce a constant voltage?

[Noopy]

The circuit is really extremly simple.
It seems like it is just a very simple differential amplifier looking at something like a zener reference with a resistor "current source".
If you balance everything as good as possible that is perhaps stable enough.