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Proposal of switching power amplifier using small‐capacity linear amplifier and LC filter
Author(s) -
Kamada Jo,
Funato Hirohito,
Ogasawara Satoshi
Publication year - 2008
Publication title -
electronics and communications in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.131
H-Index - 13
eISSN - 1942-9541
pISSN - 1942-9533
DOI - 10.1002/ecj.10161
Subject(s) - linear amplifier , direct coupled amplifier , current feedback operational amplifier , electronic engineering , amplifier , operational amplifier , cascade amplifier , rf power amplifier , computer science , power added efficiency , electrical engineering , operational transconductance amplifier , engineering , cmos
High efficiency and low noise in output voltage and current are required in audio‐video equipment, medical apparatus, and many other applications. This paper proposes a power amplifier in which a PWM inverter is used as the main circuit. In the proposed power amplifier, a hybrid filter consisting of a simple conventional type LC filter and a small‐capacity linear amplifier is connected to the inverter output. The linear amplifier is inserted in series to the filter capacitor to improve the filtering effect of the LC filter. Switching ripples and LC resonances are considerably suppressed by controlling the amplifier using the proposed method, thus implementing a low‐distortion switching power amplifier. The effects of the proposal circuit are verified by simulation and experiments. As a result, the proposed circuit achieves low noise about THD=0.68% in simulation and THD=1.5% in experiment. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 91(10): 1–10, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/ecj.10161