A linear low dropout voltage regulator is described that makes use of a depletion
mode NMOS pass transistor and of a PMOS transistor in series to the NMOS transistor
and connected to its drain. The depletion NMOS transistor assures low dropout operations,
while the series PMOS transistor allows the current regulation even under the condition
of shorted load. The same PMOS transistor may be used to disable the current in
the load without generating a negative voltage at the gate of the depletion pass
transistor. This regulator is inherently stable without the need for an output
capacitor in parallel to the load.