What is the Difference Between Power Amplifier and Voltage Amplifier?

The main difference between a power amplifier and a voltage amplifier lies in their design goals and the characteristics of the signals they handle:

Function: A voltage amplifier is designed to increase the level of input voltage, while a power amplifier is designed to boost the power level of the input signal.
Input Voltage: The input voltage of a voltage amplifier is very low, of the order of approximately a few millivolts (mV), whereas the input voltage of a power amplifier is typically between 2 to 4 volts.
Gain: The current gain offered by a voltage amplifier is generally less than that offered by a power amplifier.
Amplitude: A voltage amplifier amplifies the voltage, while a power amplifier amplifies the power of the input signal.
Signal Classification: Voltage amplifiers are also known as small signal amplifiers, while power amplifiers are often called large signal amplifiers.
Output Power: The amount of AC output power delivered by a power amplifier is significantly higher than that of a voltage amplifier.
Efficiency: Power amplifiers are generally more efficient than voltage amplifiers in terms of heat dissipation.

In summary, voltage amplifiers are designed to increase the voltage level of low-voltage input signals, while power amplifiers are designed to boost the power level of input signals, typically for driving output devices like speakers or antennas.

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What is the Difference Between Power Amplifier and Voltage Amplifier?

Comparative Table: Power Amplifier vs Voltage Amplifier

Here is a table comparing the differences between power amplifiers and voltage amplifiers:

Feature	Power Amplifier	Voltage Amplifier
Definition	A type of amplifier designed to boost the power level of the input signal.	An amplifier designed to increase the level of input signal; also called a small signal amplifier.
Alternate Name	Large signal amplifier.	Small signal amplifier.
Input Signal	High current.	Low voltage, approximately a few mV.
Output Power	High output power.	Low output power.
Signal Gain	High current gain.	Low voltage gain.
Coupling	Transformer coupled.	RC coupled.
Impedance	High load impedance, typically around 5 to 20 Ω.	Low load impedance.
Application	Used in various applications like headphone drivers, TVs, mobiles, music systems, microwave ovens, etc..	Mainly used for audio frequency signals.

In summary, power amplifiers are designed to increase the power level of the input signal, while voltage amplifiers are designed to increase the voltage level of the input signal. Power amplifiers are also called large signal amplifiers and have high output power, high current gain, and high load impedance. In contrast, voltage amplifiers, also known as small signal amplifiers, have low output power, low voltage gain, and low load impedance.

Guilherme Mazui

Guilherme Mazui is graduated in journalism from the Federal University of Minas Gerais (UFMG) and a master's degree in Communication from the University of São Paulo (USP). In addition, he has experience in advertising writing and has worked as a content editor in several companies.