In electronics, amplifiers are used to increase the amplitude of an electrical signal. Two common types of amplifiers are voltage amplifiers and power amplifiers. While both types of amplifiers amplify signals, they differ in their specific applications and design requirements. In this article, we will discuss the differences between voltage amplifiers and power amplifiers in detail.
Difference Between Voltage Amplifier and Power Amplifier
Three main differences between voltage amplifier and power amplifier are:
- Amount of power that they can deliver
- The design requirements
- The power rating
Amount of power that they can deliver
- Voltage amplifiers are designed to increase the voltage level of a low-level signal without significantly altering its power or current. In contrast, power amplifiers are designed to deliver a high-power signal that can drive a load, such as a loudspeaker or motor.
- The output of a voltage amplifier is typically a high-impedance signal that is suitable for driving the input of another amplifier or a signal-processing circuit. While, the output of a power amplifier is typically a low-impedance signal that can deliver a high current to the load.
- Voltage amplifiers are used in a wide range of applications, such as audio preamplifiers, microphone preamplifiers, and instrumentation amplifiers. While, power amplifiers are used in a variety of applications, such as audio amplifiers, motor drivers, and radio-frequency transmitters.
The design requirements of a voltage amplifier and a power amplifier
- Voltage amplifiers are designed to achieve a high gain with low distortion and noise, while power amplifiers are designed to deliver a high power output with minimal distortion and heat dissipation.
- In voltage amplifier, the amplifier must also have a high input impedance to avoid loading the signal source. While in power amplifier, The amplifier must also have a low output impedance to match the impedance of the load and minimize losses in the output stage.
The power rating of a power amplifier
- Power amplifiers are rated in watts, which is a measure of the maximum power that the amplifier can deliver to the load. While, voltage amplifiers are rated in terms of their voltage gain, which is a measure of how much the input voltage is amplified by the amplifier.