Embedded Single-Inductor Bipolar-Output DC-DC Converter in Class-D Amplifier for Low Common Noise

This paper proposes a high efficiency class-D amplifier (CDA) with embedded single-inductor bipolar output (SIBO) power module. The characteristics of SIBO converter's bipolar outputs not only suppress equivalent common-mode noise but also remove several large external bulky components in conventional boost supply CDA systems. Since bipolar outputs in the SIBO provide independent driving capability, CDA is capable of operating in both single-ended and bridge-tide load configurations. Furthermore, the proposed dynamic voltage boosting technique adjusts the SIBO output voltage level according to the CDA's output level with 5% power efficiency improvement. Peak total harmonic distortion plus noise performance is 0.012%. Peak power efficiency of SIBO and CDA is 89% and 93.2%, respectively.