Patent ID: 7227390

Claim:
A circuit for driving for a class D audio power amplifier, comprising: a low-voltage detect circuit that is arranged to monitor a supply voltage to detect a low supply voltage condition; and further arranged to provide a low-voltage detect signal based, in part, on the monitoring of the supply voltage; and a driver circuit that is arranged to drive a power transistor based, in part, on the supply voltage; and further arranged to adaptively adjust a drive strength of the driver circuit based on the low-voltage detect signal such that the drive strength is increased if the low supply voltage condition is detected, wherein the low-voltage detect circuit is arranged to assert the low-voltage detect signal substantially if the supply voltage is below a first pre-determined voltage level, the driver circuit is arranged to increase the drive strength if the low-voltage detect signal is asserted, and wherein the driver circuit includes: a first driver including an input and an output; and a second driver including an input that is coupled to the input of the first driver, an output that is coupled to the output of the first driver, and an enable input that is coupled to the low-voltage detect circuit, wherein the second driver is arranged to be enabled if the low-voltage detect signal is asserted, and further arranged to be disabled if the low-voltage detect signal is unasserted.