A 1.5W 10V-output Class-D amplifier using a boosted supply from a single 3.3V input in standard 1.8V/3.3V 0.18μm CMOS

In this paper, a complete high-voltage concept is presented, designed in a low- voltage CMOS technology, using only the nominal voltage as input. A test chip has been developed with an inductive DC-DC converter generating a 10V output from a single 3.3V input in a standard 1.8V/3.3V 0.18μm CMOS technology. The generated 10V serves as a supply for an on-chip Class-D output stage, able to deliver 1.5W. The 10V is protected by a custom high-voltage ESD clamp. Reliable operation of the low-voltage devices is guaranteed, including process, power supply and temperature variations, without the need for special startup circuits.