A High-Performance Fast Switching Charge Dump Assisted Class- K^ Audio Amplifier

A new Class- K* audio amplifier with high-power efficiency and high fidelity is integrated in a 0.35-μm CMOS process. It proposes a new topology connected Class-D amplifier with fast-switching charge-dump (FSCD) amplifier in parallel. The integration of the amplifier requires neither analog buffer a...

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Bibliographic Details
Published in:IEEE transactions on circuits and systems. I, Regular papers Vol. 57; no. 6; pp. 1122 - 1133
Main Authors: Kwang-Chan Lee, Chang-Seok Chae, Jin-Yong Jeon, Kang-Ho Lee, Gyu-Hyeong Cho
Format: Journal Article
Language:English
Published: IEEE 01.06.2010
Subjects:
Audio amplifier
Bandwidth
Circuit topology
Class-AB
Class-D
Class-K
CMOS process
efficiency
fidelity
Frequency response
High power amplifiers
Linearity
Operational amplifiers
Power capacitors
Pulse-Width-Modulation (PWM)
Switches
Total harmonic distortion
total harmonic distortion (THD) and CMOS
ISSN:1549-8328, 1558-0806
Online Access:Get full text
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Summary:A new Class- K* audio amplifier with high-power efficiency and high fidelity is integrated in a 0.35-μm CMOS process. It proposes a new topology connected Class-D amplifier with fast-switching charge-dump (FSCD) amplifier in parallel. The integration of the amplifier requires neither analog buffer amplifier nor a complex compensation circuit needed in hybrid audio amplifier (Class-K). The FSCD amplifier composed of comparators and switches works at a high-switching frequency in order to absorb the distortion caused by Class-D amplifier switching. Thus, this assists the audio amplifier to have good linearity under switching operation. With the proposed topology, the audio amplifier has a flat frequency response with - 3-dB bandwidth of 60 KHz and is capable of delivering up to 257 mW into 4.1-Ω load with maximum efficiency of 81%. A typical total harmonic distortion plus noise (THD+ N ) is less than 0.1% at the power level over 25 mW within the audio frequency range (20 Hz-20 kHz), and the minimum THD+ N is 0.025% with the audio input frequency of 1 kHz at the output power of 114 mW.
ISSN:1549-8328
1558-0806
DOI:10.1109/TCSI.2009.2028644