SLOS948 February 2019 TAS6424M-Q1
The amplifier outputs are driven by high-current LDMOS transistors in an H-bridge configuration. These transistors are either fully off or fully on. The result is a square-wave output signal with a duty cycle that is proportional to the amplitude of the audio signal. An LC demodulation filter is used to recover the audio signal. The filter attenuates the high-frequency components of the output signals that are out of the audio band. The design of the demodulation filter significantly affects the audio performance of the power amplifier. Therefore, to meet the system THD+N requirements, the selection of the inductors used in the output filter should be carefully considered.