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 comprises 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).

主权项

1. A voltage regulator, comprising:
an operational amplifier; a gm enhanced current buffer driver; an output power driver, wherein the current buffer driver is coupled between the operational amplifier and the output power driver; a current feedback circuit coupled between the output power driver and the current buffer driver; and a feedback loop coupled between the output power driver and the operational amplifier.