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Journal Article

An Active Load and Test Method for Evaluating the Efficiency of Audio Power Amplifiers

Authors: Dymond, Harry C. P.; Mellor, Phil

Journal of the Audio Engineering Society · Volume 58 · Issue 5 · pp. 394–408 · May 2010

Abstract

Automated testing of amplifier efficiency is made fast and flexible by using an active load that can simulate various conditions. The proposed method uses a controlled load that can range from 4 to 50 ohms with a phase between –60 and +60 degrees for frequencies from 20 Hz to 20 kHz. This active load has been used in an automated test procedure to capture efficiency maps of class-B and class-D amplifiers over a full range of operating conditions. While test results showed that the class-D amplifier outperformed the class-B amplifier, real-world efficiency was significantly lower than might be expected because of power supply efficiency, as well as the power consumption of driving stages and peripheral circuits.

Details

Publication
Journal of the Audio Engineering Society
Volume
58
Issue
5
Pages
394–408
Publication date
May 6, 2010
Affiliation
Electrical and Electronic Engineering, University of Bristol, Bristol, UK (See document for exact affiliation information.)
Type
Journal Article