Abstract: A boost class-D amplifier includes a PWM modulator, a boost level controller coupled to the PWM modulator, a pre-driver coupled to the PWM modulator and the boost level controller, a system voltage source, an inductor coupled to the system voltage source, a first switch, a second switch, a third switch, a fourth switch, a first diode coupled between the third switch and a voltage ground, a second diode coupled between the fourth switch and the voltage ground, and a capacitor coupled between the first switch and the fourth switch. The PWM modulator is for receiving an input signal and generating a first modulated signal accordingly. The boost level controller is for receiving the first modulated signal and generating a second modulated signal accordingly. The pre-driver is for receiving the first modulated signal and the second modulated signal and generating control signals accordingly.

Abstract: A data first-in first-out (FIFO) circuit includes a register unit, a plurality of data multiplexers, and an output multiplexer. The register unit includes a plurality of decoders and a plurality of N registers. The decoders are used for outputting a plurality of decoded signals in response to a plurality of corresponding input control signals and at least one input enabling signal. The N registers are configured to receive input data in response to the corresponding decoded signals from the corresponding decoders. The data multiplexers each are coupled to M ones of the registers, wherein N and M are positive integers, N is equal to or greater than four, M is equal to or greater than two, and N is greater than M. The output multiplexer, coupled to the data multiplexers, is used for providing a corresponding output from the data multiplexers sequentially.