A low drop out series regulator circuit for generating an output voltage
that does not rely on voltage feedback or require a capacitor for stable
operation includes first and second current sources connected in series
between a supply voltage and ground. A resistor is connected between and
in series with the first and second current sources, and a reference
voltage is generated across the resistor by the current from the first
current source. A first transistor is connected between the ground and a
first node located between the resistor and the second current source. A
current mirror circuit is connected between the supply voltage and the
first transistor. A current sense transistor is connected between the
current mirror circuit and an output terminal. An output transistor is
connected between the supply voltage and the output terminal. The output
voltage generated at the output terminal is equal to the reference
voltage.