Category: 2. Amplifier

Amplifiers are classified into classes according to their construction and operating characteristics Not all amplifier designs are the same. There is a clear distinction made between the various Amplifier Classes regarding the way in which their power output stages are configured and operate. The main operating characteristics of an ideal amplifier are linearity, signal gain, efficiency and…

Emitter Resistance connected to the emitter terminal of a transistor amplifier can be used to increases the amplifiers bias stabilisation The aim of any amplifier is to stabilise the DC biased input voltage and amplify only the required AC signal. An emitter resistance connected to the emitter terminal of a transistor achieves this by increasing…

Amplifiers are used extensively in electronic circuits to make an electronic signal bigger without affecting it in any other way Generally we think of Amplifiers as audio amplifiers in the radios, CD players and stereo’s we use around the home. In this amplifiers summary section we looked at the amplifier circuit based on a single bipolar transistor as…

Crossover Distortion is a common feature of Class-B amplifiers where the non-linearities of the two switching transistors do not vary linearly with the input signal Distortion is the inexact reproduction of an input signal at the output of an amplifier. Due to their two-stage design, push-pull amplifiers suffer from crossover distortion of the output waveform…

Class-B Amplifiers use two or more transistors biased in such a way so that each transistor only conducts during one half cycle of the input waveform To improve the full power efficiency of the previous Class A amplifier by reducing the wasted power in the form of heat, it is possible to design the power…

Common emitter amplifiers are the most commonly used type of amplifier as they can have a very large voltage gain The common emitter class-A amplifier is designed to produce a large output voltage swing from a relatively small input signal voltage of only a few millivolt’s and are used mainly as “small signal amplifiers” as…

Amplifier Distortion can take on many forms such as Amplitude, Frequency and Phase Distortion due to Clipping For a signal amplifier to operate correctly without any amplifier distortion of the output signal, it requires some form of DC Bias on its Base or Gate terminal. A DC bias is required so that the amplifier can…

Common Source JFET Amplifier uses junction field effect transistors as its main active device offering high input impedance characteristics The common source JFET amplifier has one important advantage compared to the common-emitter BJT amplifier in that the FET has an extremely high input impedance and along with a low noise output makes them ideal for…

The most common amplifier configuration for an NPN transistor is that of the Common Emitter Amplifier circuit Transistor amplifier’s amplify an AC input signals that alternates between some positive value and a corresponding negative value. Then some way of “presetting” a common emitter amplifier circuit configuration is required so that the transistor can operate between…

Introduction to the Amplifier An amplifier is an electronic device or circuit which is used to increase the magnitude of the signal applied to its input Amplifier is the generic term used to describe a circuit which produces and increased version of its input signal. However as we will see in this introduction to the amplifier…