A low drop-out voltage regulator having a pass device (Mp), an error
amplifier (M1-M51) and a double regulation loop including DC feedback
loop (R1, R2) and an AC feedback loop (Rf, Cf) including a high pass
filter (Cf). Combining these two loops creates an ultra low frequency
internal pole which makes the regulator stable substantially independent
of the output bypass capacitor's value. This provides the following
advantages: allows the use of very low bypass capacitors; allows to
extend the PSRR frequency behavior; allows an increase in the regulator's
efficiency (reduced power consumption on heavy loads).