Power Amplifier

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What Does Power Amplifier Mean?

A power amplifier (PA) is defined by the ratio between the power supplied to the load and the power provided to the circuit by the source. A PA is categorized on the basis of its power rating, which is measured in watts (W). The power rating can be stated in terms of load impedance (ohm) across which the output power is measured.

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Techopedia Explains Power Amplifier

Modern electronic circuits give high power amplification when low impedance is used (in the case of speakers), but this is not always recommended. Generally, the rated power output of an amplifier is said to be its peak output value. For example, if the PA is rated at 20 W, then the output can range from 0 to 20 (i.e., the maximum rated value). In the case of an overdriven input, the PA can give an output power that is many times higher than the maximum rated value, but, at the same time, the output signal quality decreases. Power amplifiers are used in a number of everyday appliances such as audio speakers and microwave ovens.

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Margaret Rouse
Technology Expert
Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.