Class D Amplifiers (CDAs) : PWM-in-PWM-out CDA, Filterless Bang-Bang CDA, and high-frequency high-efficiency CDA for Envelope Tracking

Abstract

This chapter is largely extracted from the author's publication [101], "Analysis and design of PWM-in-PWM-out Class D Amplifiers" published in the proceedings of the IEEE 57th International Midwest Symposium on Circuits and Systems (MWSCAS), 2014.Following Chapter 1 and Chapter 2, we will delineate in this chapter our research pertaining to the PWM-in PWM-out (PIPO) CDAs to feature improved performance. Specifically, we analytically investigate the fidelity (qualified by THD) and the noise immunity (qualified by PSRR) of the PIPO CDA and derive their mechanisms.On the basis of our investigations, we design a PIPO CDA whose THD and PSRR parameters are notably superior over its conventional counterparts. Computer simulations of the designed CDA are thereafter presented to corroborate the analytical results and to demonstrate/verify the performance of the proposed PIPO CDA. Low-Power High-Efficiency Filterless Bang-Bang Class D AmplifierThis chapter is largely extracted from the author's publication [104], "A novel lowpower high-efficiency 3-state filterless Bang-Bang class D amplifier" published in the proceedings of the IEEE International Conference on Electronics, Circuits, and Systems (ICECS), 2015.