What will happen if resistor is added to the emitter of a common emitter amplifier?

What will happen if resistor is added to the emitter of a common emitter amplifier?

The addition of this emitter resistor means that the transistors emitter terminal is no longer grounded or at zero volt potential but sits at a small potential above it given by the Ohms Law equation of: VE = IE x RE.

What is the purpose of resistor connected to the base of transistor in common emitter amplifier?

The emitter resistor prevents current from increasing when temperature does. When temperature increases, the current increases. This causes the Voltage across the resistor to increase. So the Base-emittet Voltage of the Transistor decreases, which causes the Current through the transistor to decrease again.

Why common emitter amplifier is widely used?

Common emitter transistors are used most widely, because a common emitter transistor amplifier provides high current gain, high voltage gain and high power gain. This type of transistor gives for a small change in input there is small change in output.

What is application of CE configuration?

Common-emitter amplifiers are also used in radio frequency circuits, for example to amplify faint signals received by an antenna. In this case it is common to replace the load resistor with a tuned circuit. This may be done to limit the bandwidth to a narrow band centered around the intended operating frequency.

What is the purpose of the emitter resistor in a common emitter amplifier?

Here, r e is the intrinsic emitter resistance, ie the reciprocal of the transconducance. If the input signal is large enough, it will substantially modulate the collector current I C, and hence the gain. If the gain depends on input signal level, that is precisely a non-linearity!

What is the base bias of an emitter resistor?

If the emitter resistor is 220 Ω (for example), a DC current of 2.73 mA flows from the collector into the emitter and then through the resistor and, it would drop about 0.601 volts across it. It then follows that the base-bias voltage would need to be about 0.601 volts plus about 0.7 volts (internal base-emitter volt-drop).

What is the transconductance of a common emitter amplifier?

The voltage gain, A, of the common emitter amplifier can be expressed as the ratio of load resistor R L to the small signal emitter resistance r e. The transconductance, gm, of the transistor is a function of the collector current I C and the so called thermal voltage, kT/q which can be approximated by around 25 mV or 26 mV at room temperature.

How does adding a degeneration resistor improve an amplifier?

Adding the emitter degeneration resistor has improved the stability of the DC operating point at the cost decreased amplifier gain. A higher gain for AC signals can be restored to some extent by adding capacitor C 2 across the degeneration resistor R E as shown in figure 9.