Abstract: A power supply system uses improved Class G amplifier architecture for high bandwidth operation with low distortion. The power supply system switches between multiple power supply rails, depending on the signal level handled by the power supply system. The lowest usable supply rail voltage is chosen to minimize power dissipation in the output driver, thus optimizing efficiency. Each supply rail has an associated driver capable of sourcing current to the amplifier output. When a supply rail is selected, its associated driver is enabled and other driver(s) not associated with the selected supply rail are disabled via separate disable control signals. The disabling of the deselected driver may be delayed until current above a predetermined threshold is sensed at the output of the enabled driver. In addition, the frequency of switching between the power rails may be limited via various means designed to limit distortion in the power supply system.

Abstract: A power supply system uses improved Class G amplifier architecture for high bandwidth operation with low distortion. The power supply system switches between multiple power supply rails, depending on the signal level handled by the power supply system. The lowest usable supply rail voltage is chosen to minimize power dissipation in the output driver, thus optimizing efficiency. Each supply rail has an associated driver capable of sourcing current to the amplifier output. When a supply rail is selected, its associated driver is enabled and other driver(s) not associated with the selected supply rail are disabled via separate disable control signals. The disabling of the deselected driver may be delayed until current above a predetermined threshold is sensed at the output of the enabled driver. In addition, the frequency of switching between the power rails may be limited via various means designed to limit distortion in the power supply system.