A circuit for adaptively adjusting the drive strength of output power transistors in a class D amplifier is provided. The circuit includes a driver circuit and a low-voltage detect circuit. The low-voltage detect circuit is arranged to assert a low-voltage detect signal if a low supply voltage condition is detected. The driver circuit is arranged to increase the drive strength if the low-voltage detect signal is asserted. The driver circuit includes a first driver and a second driver. The second driver is enabled if the low-voltage detect signal is asserted, and disabled if the low-voltage detect signal is unasserted.