This paper presents a novel design of an ultra-broad-band class-D power amplifier (PA). The proposed architecture is based on the concept of the ripple buck converter after employing some modifications to facilitate supporting bandwidths up to tens of MHz. The input frequency range covered using the proposed class-D PA is from 0.5MHz up to 30MHz. A wide-band transformer has been used to convert the differential outputs of the class-D PA to single-ended load. The design has been implemented and fabricated using a CMOS 0.13μm technology. It occupies an active area of 0.836mm² and operates from a single 1.2V supply. The measurement results validates the functionality of the proposed class-D PA with good linearity and peak efficiency of 58% at 140mW of output power. This has been achieved using few off-chip passive components.