Amplifiers may be classified based on the type of signal that they amplify. Thus, an amplifier that amplifies voltage signals is a voltage amplifier, while a buffer amplifier is one that amplifies current signals. An amplifier that amplifies both the voltage and current is classified as a power amplifier.
Amplifiers consist of active devices (such as bipolar and field-effect transistors) that can be connected such that there is a common terminal between the input and the output. One common way of classifying amplifiers is in terms of their common terminal connection. For instance, a common-emitter amplifier means that the active device is a bipolar transistor whose emitter terminal is common to the input and the output side.
Amplifiers may also be classified according to the frequency range of the signals they can amplify. Categories under such a classification include: 1) DC amplifiers; 2) Audio Frequency (AF) amplifiers – 20 Hz to 20 kHz; 3) Video amplifiers – several MHz; and 4) Ultra High Frequency (UHF) amplifiers – up to a few GHz.
Amplifiers may be classified according to their basic function or output characteristics. Some of these functional classifications are as follows:
- servo amp : an amp with an integrated feedback loop to actively control the output at the desired level
- linear amp : an amp with a precise amplification factor over a wide range of frequencies, often used to boost signals for relay in communications systems
- non-linear amp : an amp that amplifies only a specific narrow or tuned frequency, to the exclusion of all other frequencies
- RF amp : an amp designed for use in the radio frequency range of the electromagnetic spectrum, often used to increase the sensitivity of a receiver or the output power of a transmitter
- audio amp : an amp designed for use in reproducing audio frequencies, with special considerations made for driving speakers
- operational amp : a low power amp that can perform mathematical operations
Audio amplifiers are sometimes classified by the method used in the coupling of the signal at the input, output, or between stages. Different types of coupling methods include: the R-C coupled amplifier; the L-C coupled amplifier; the transformer-coupled amplifier; and the direct-coupled amplifier.
Another way of classifying amplifiers is by the type of load that they drive: 1) untuned amps - amplify audio and video with no tuning required; 2) tuned amps (RF amps) - amplify a single radio frequency or band of frequencies.
A letter system for classifying amplifiers also exists, wherein amplifiers fall under class A, class B, class C, and so on. This classification system is based on the amount of time that the amplifier's active components are conducting electricity, with the duration measured in terms of the number of degrees of the sine wave test signal.
7 comments:
Classification by Signal Type:
Amplifiers may be classified based on the type of signal that they amplify. Thus, an amplifier that amplifies voltage signals is a voltage amplifier, while a buffer amplifier is one that amplifies current signals. An amplifier that amplifies both the voltage and current is classified as a power amplifier.
Classification by Common Terminal Connection:
Amplifiers consist of active devices (such as bipolar and field-effect transistors) that can be connected such that there is a common terminal between the input and the output. One common way of classifying amplifiers is in terms of their common terminal connection. For instance, a common-emitter amplifier means that the active device is a bipolar transistor whose emitter terminal is common to the input and the output side.
Classification by Frequency Range:
Amplifiers may also be classified according to the frequency range of the signals they can amplify. Categories under such a classification include: 1) DC amplifiers; 2) Audio Frequency (AF) amplifiers – 20 Hz to 20 kHz; 3) Video amplifiers – several MHz; and 4) Ultra High Frequency (UHF) amplifiers – up to a few GHz.
Classification by Function:
Amplifiers may be classified according to their basic function or output characteristics. Some of these functional classifications are as follows:
- servo amp : an amp with an integrated feedback loop to actively control the output at the desired level
- linear amp : an amp with a precise amplification factor over a wide range of frequencies, often used to boost signals for relay in communications systems
- non-linear amp : an amp that amplifies only a specific narrow or tuned frequency, to the exclusion of all other frequencies
- RF amp : an amp designed for use in the radio frequency range of the electromagnetic spectrum, often used to increase the sensitivity of a receiver or the output power of a transmitter
- audio amp : an amp designed for use in reproducing audio frequencies, with special considerations made for driving speakers
- operational amp : a low power amp that can perform mathematical operations
Classification by Interstage Coupling Method:
Audio amplifiers are sometimes classified by the method used in the coupling of the signal at the input, output, or between stages. Different types of coupling methods include:
the R-C coupled amplifier;
the L-C coupled amplifier;
the transformer-coupled amplifier;
and the direct-coupled amplifier.
Classification by type of Load:
Another way of classifying amplifiers is by the type of load that they drive:
1) untuned amps - amplify audio and video with no tuning required;
2) tuned amps (RF amps) - amplify a single radio frequency or band of frequencies.
Classification by Angle Flow or Conduction Angle:
A letter system for classifying amplifiers also exists, wherein amplifiers fall under class A, class B, class C, and so on. This classification system is based on the amount of time that the amplifier's active components are conducting electricity, with the duration measured in terms of the number of degrees of the sine wave test signal.
Post a Comment