Patent ID: 6255909
Filing Date: 2001-07-03
Classification: H03F

Abstract:
A class AB power amplifier comprising:an input gain stage; anda PMOS output transistor having its source connected to a first supply voltage Vdd and having its gate driven by a PMOS driver transistor in response to a positive input signal generated via the input gain stage and further having a NMOS output transistor having its source connected to a second supply voltage Vss and further having its gate driven by a NMOS driver transistor in response to a negative input signal generated via the input gain stage, wherein the output transistors and the driver transistors are configured as a class AB output stage, and further wherein the PMOS output transistor and the NMOS output transistor are selected to have predetermined gate-source parasitic capacitance values, such that the gate-source parasitic capacitance of the PMOS output transistor and the gate-source parasitic capacitance of the NMOS output transistor combine to achieve a class AB power amplifier having a single dominant pole.