Title :
Ripple feedback filter suitable for analog/digital mixed-mode audio amplifier for improved efficiency and stability
Author :
Kim, Nam-In ; Jung, Sang-Hwa ; Ryoo, Ji-Yeoul ; Cho, Gyu-Hyeong
Author_Institution :
Korea Adv. Inst. of Sci. & Technol. (KAIST), Daejeon, South Korea
Abstract :
A new ripple feedback filter is presented for analog/digital mixed-mode amplifier (MMA) among audio applications. MMA is composed of two amplifiers: one is analog amplifier responsible for high fidelity and the other is digital switching amplifier in charge of high efficiency. To improve both total harmonic distortion (THD) and efficiency, a passive RLC filter is needed at the output side of the digital switching amplifier. A conventional filter, however, causes phase delay, which worsens current loop stability and makes the normal operation of MMA impossible. A ripple feedback filter is newly suggested to solve this problem, obtaining excellent efficiency and low THD.
Keywords :
analogue circuits; audio-frequency amplifiers; digital circuits; filters; harmonic distortion; switching circuits; 2 kW; analog amplifier; analog/digital mixed-mode amplifier; current loop stability; digital switching amplifier; efficiency improvement; high efficiency; high fidelity; phase delay; ripple feedback filter; total harmonic distortion improvement; Current supplies; Digital filters; Feedback; High power amplifiers; MOS devices; Operational amplifiers; Power amplifiers; Stability; Switching frequency; Voltage;
Conference_Titel :
Power Electronics Specialists Conference, 2002. pesc 02. 2002 IEEE 33rd Annual
Print_ISBN :
0-7803-7262-X
DOI :
10.1109/PSEC.2002.1023845
