USB regulator with current buffer to reduce compensation capacitor size and provide for wide range of ESR values of external capacitor

摘要

A voltage regulator has a large gm current buffer driver added between a first stage of an operation amplifier and a last stage power transistor. This current buffer allows a significant reduction in the maximum internal and external compensation capacitances needed for regulator stability. The current buffer compensation circuit allows a wide range of external capacitor sizes that increases the flexibility in choosing the external capacitor types (with low to high ESR ratings).