Method and apparatus for improving power supply rejection in amplifier rail to rail output stages

摘要

Apparatus and methods to provide high supply rejection and rail-to-rail output swing at the output of an amplifier circuit. A power source supplies power to a low noise regulator and to a differential amplifier output stage. The low noise regulator supplies power to an input stage that is coupled to the output stage, and also provides a reference to the output stage for power supply noise reduction purposes. This configuration of first and second circuits give the output both full rail-to-rail swing and good supply rejection in both stages. Exemplary embodiments are disclosed.