A low drop out (LDO) regulator that includes a novel error amplifier,
which is arranged with a first stage that employs both NMOS and PMOS
devices that are similarly doped in differential pairs and a second stage
that operates with NMOS and PMOS devices in a push-pull arrangement. In
addition to the error amplifier, the LDO regulator can also include a
startup circuit coupled to an enable voltage, a reference filter circuit
coupled to a reference voltage, an output circuit, a quiescent current
control circuit, and a pulse generator circuit. Also, an internal RC
network is provided to compensate for phase shift. The integrated
operation of the components of the regulator enables stable and fast
operation of an LDO regulator with no external capacitors connected to
the input or output terminals.