Patent ID: 7733180

Claim:
An apparatus having a zero-pole that is dependant on an equivalent series resistance (ESR) and a load, the apparatus comprising: an amplifier stage that receives a first input voltage and a bias voltage, wherein the amplifier stage has an output node, and wherein the amplifier stage includes a plurality of internal transistors; an intermediate stage that is coupled to the output node of the amplifier stage, wherein the intermediate stage outputs an intermediate voltage to an intermediate node; a first capacitor coupled between at least one of the internal transistors at an internal node and the intermediate node; a power transistor coupled between a second input voltage and the intermediate node; a second capacitor coupled between the intermediate node and the power transistor, wherein the second capacitor provides a third input voltage to the power transistor, wherein the ratio of the capacitance of the first capacitor to the capacitance of the second capacitor controls the position of the zero-pole; and a feedback stage coupled to the intermediate node and to the amplifier stage, wherein the feedback stage is adapted to output an output voltage to a load, and wherein the feedback stage provides a feedback voltage to the amplifier stage.