Class-D amplifiers exhibit high efficiency in spite of their simple implementation and, therefore, they are often used in portable devices with typical THD performance of the order of -65 dB. Presently, the possibility of using class-D amplifiers in applications requiring better THD (THD < -85 dB) is being investigated, in consideration of their possible application in huge markets (like high-performance audio). For this reason, the THD performance of conventional class-D structures is not enough and new topologies have to be analyzed and implemented. In this paper, high-order class-D structures have been investigated to achieve the target THD performance. Among them, we selected a 3rd-order fully-differential class-D amplifier, which has been implemented in a 0.18-μm CMOS technology, starting from a previously available 1st-order class-D structure. The measurements on the realized 3rd-order device show a THD ≈ -91 dB with -1 dB FS input signal, about 30 dB better than the 1st-order structure. © 2011 IEEE.
Cartasegna, D., Malcovati, P., Crespi, L., Lee, K., Murukutla, L., Baschirotto, A. (2011). An Audio 91-dB THD Third-Order Fully-Differential Class-D Amplifier. In Proceedings of IEEE European Solid-State Circuits Conference (ESSCIRC `11) (pp.91-94). The Institute of Electrical and Electronics Engine [10.1109/ESSCIRC.2011.6044922].
An Audio 91-dB THD Third-Order Fully-Differential Class-D Amplifier
BASCHIROTTO, ANDREA
2011
Abstract
Class-D amplifiers exhibit high efficiency in spite of their simple implementation and, therefore, they are often used in portable devices with typical THD performance of the order of -65 dB. Presently, the possibility of using class-D amplifiers in applications requiring better THD (THD < -85 dB) is being investigated, in consideration of their possible application in huge markets (like high-performance audio). For this reason, the THD performance of conventional class-D structures is not enough and new topologies have to be analyzed and implemented. In this paper, high-order class-D structures have been investigated to achieve the target THD performance. Among them, we selected a 3rd-order fully-differential class-D amplifier, which has been implemented in a 0.18-μm CMOS technology, starting from a previously available 1st-order class-D structure. The measurements on the realized 3rd-order device show a THD ≈ -91 dB with -1 dB FS input signal, about 30 dB better than the 1st-order structure. © 2011 IEEE.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.