Penguat Audio Kelas D dengan Umpan Balik Tipe Butterworth

Abstract

A class D amplifier would, in ideal sense, amplify signals without any noises and distortions which yield 100% efficiency and 0% Total Harmonic Distortion (THD). However, class D amplifiers have some drawbacks that lead to nonlinearity and increasing THD. Therefore, a feedback mechanism was employed to enhance THD performance of amplifier. Some feedback techniques have been using first order filter in the feedback path to retrieve audio signals. This research proposed a second order filter with Butterworth approach. A power amplifier was realized using full-bridge amplifier with MOSFETs to provide greater power. This class D amplifier was designed to meet following specifications: maximum output power up to 32.6 W with an 8 Ω load, sensitivity of 90 mV/W, frequency response ranging from 20 Hz – 20 kHz with tolerance ± 1 dB, THD as low as 1.1 %, SNR up to 90.16 dB, and efficiency of 82.1 %.

Keywords

• Class D Amplifier
• Feedback
• Butterwort
• Butterworth
• Total Harmonic Distortion