A class-D, or switching, amplifier is a high-efficiency amplifier often used to amplify an audio signal. In a system using a class-D amplifier, an analog input signal is transformed into a series of pulses having different pulse widths (i.e., a pulse width modulated signal). The class-D amplifier amplifies the pulse width modulated signal to, for example, drive an audio speaker. The high efficiency of a class-D amplifier is partly realized from low quiescent current generated when the input signal to the amplifier is idle and partly realized from lower resistances of the output transistors when the transistors are conducting. The input signal is often idle when typical audio signals are input to the amplifier, because many audio signals include significant amounts of idle time. A class-D amplifier operates in a switching mode, which reduces or eliminates quiescent currents as compared to an active-resistance transistor operation used in class-AB amplifiers. Reduced quiescent current, in turn, reduces overall power consumption of the class-D amplifier over that of the class-AB amplifier.