Efficiency of Current-Mode Class-D Amplifiers with Delta-Sigma Modulated Drive Signals

This paper describes the losses and efficiency deteriorations due to several non-idealities of a current-mode class-D amplifier driven by a Delta-Sigma pulse sequence. The computation of the total efficiency of the amplifier is presented. Finally the results are verified by designing and measuring an amplifier driven by a pulse sequence with 50% duty cycle and a frequency of 30 MHz. The measured efficiency of 55.6% fits the calculated value of 58.3%.