What is the reason why common collector is used for impedance matching?

Common collector configuration, also known as emitter follower provides high input impedance and low output impedance. So they are used for the purpose of impedance matching. In common collector configuration, the collector terminal is common to both input and output terminals.

Why buffer amplifier is used?

A buffer amplifier (sometimes simply called a buffer) is one that provides electrical impedance transformation from one circuit to another, with the aim of preventing the signal source from being affected by whatever currents (or voltages, for a current buffer) that the load may be produced with.

What is the use of buffer?

Buffers. A buffer is an aqueous solution containing a weak acid and its conjugate base or a weak base and its conjugate acid. A buffer’s pH changes very little when a small amount of strong acid or base is added to it. It is used to prevent any change in the pH of a solution, regardless of solute.

What can a common collector amplifier be used for?

(April 2009) ( Learn how and when to remove this template message) Figure 1: Basic NPN common collector circuit (neglecting biasing details). In electronics, a common collector amplifier (also known as an emitter follower) is one of three basic single-stage bipolar junction transistor (BJT) amplifier topologies, typically used as a voltage buffer.

What is the output resistance of a common collector?

Dynamic output resistance is defined as the ratio of change in output voltage or emitter voltage (VEC) to the corresponding change in output current or emitter current (IE), with the input current or base current (IB) kept at constant. The output resistance of common collector amplifier is low.

How is the circuit of a common collector explained?

The circuit can be explained by viewing the transistor as being under the control of negative feedback. From this viewpoint, a common collector stage (Fig. 1) is an amplifier with full series negative feedback. In this configuration (Fig. 2 with β = 1), the entire output voltage V OUT is placed contrary and in series with the input voltage V IN.

What makes an emitter follower a common collector?

The emitter follower or common collector circuit provides an ideal buffer amplifier and it is easy to design the circuit. The common collector circuit configuration is more widely known as the emitter follower and it provides a high input impedance and a low output impedance.