A transistor current amplifier is an electronic circuit that uses a transistor to amplify the current flowing through it. The transistor is a three-terminal device that can be used as a switch or an amplifier and is commonly used in electronic circuits to amplify signals or control the flow of current.
Transistor current amplifiers are an essential building block in modern electronics, and their ability to amplify current has enabled the development of a wide range of electronic devices and systems.
Features of Transistor Current Amplifiers
- High voltage gain
- High input impedance
- Low output impedance
- Linear response
- High frequency response
- Low cost
Types of Transistor Current Amplifiers
There are several types of transistor current amplifiers, each with different characteristics and advantages. Here are some of the most common types:
Common Emitter Amplifier
In this configuration, the input signal is applied to the base of the transistor, and the output signal is taken from the collector. The emitter is typically connected to ground, and a load resistor is connected to the collector. Common emitter amplifiers provide high voltage gain and are commonly used in audio amplifiers.
Common Base Amplifier
In this configuration, the input signal is applied to the emitter of the transistor, and the output signal is taken from the collector. The base is connected to ground, and a load resistor is connected to the collector. Common base amplifiers provide high input impedance and are commonly used in high frequency applications.
Common Collector Amplifier
In this configuration, the input signal is applied to the base of the transistor, and the output signal is taken from the emitter. The collector is typically connected to a voltage source, and a load resistor is connected to the emitter. Common collector amplifiers provide low output impedance and are commonly used as voltage followers.
Darlington Amplifier
In this configuration, two transistors are connected in a common emitter configuration, with the emitter of the first transistor connected to the base of the second transistor. Darlington amplifiers provide high current gain and are commonly used in power amplifiers.
Cascode Amplifier
In this configuration, two transistors are connected in a common emitter configuration, with the collector of the first transistor connected to the base of the second transistor. Cascode amplifiers provide high voltage gain and low input and output impedance, and are commonly used in high frequency applications.
Applications
- Audio amplifiers
- Motor control
- Power supplies
- Switching circuits
- Logic gates
- Sensors