2007-03-21 16:23:46 · 6 answers · asked by David Junior 3 in Science & Mathematics ➔ Engineering
A common emitter BJT amplifier has the emitter grounded. It may be directly connected to the ground or it may be connected through a small emitter resistance. The resistance decreases the overall voltage gain, but increases stability. This resistance is shorted in the AC equavalent circuit by using a emitter bypass capacitor. Any amplifier circuit where the emitter is directly or through a resistor is connected to the ground is a common emitter amplifier.
So why is it called a common emiiter amplifier ? You measure the input voltage at base with respect to ground. You measure the output voltage at collector with respect to ground. But the emitter is the ground. So both the input and output circuit have the emitter as common. So it is called a common emitter amplifier.
Hope this was helpful.
2007-03-25 01:38:58 · answer #1 · answered by rhapsody 4 · 1⤊ 0⤋
Emitter Definition
2016-10-21 01:23:57 · answer #2 · answered by ? 4 · 0⤊ 0⤋
The emitter is connected to both the input and the output. It's also connected to signal ground. The common emitter configuration can amplify both voltage and current. But it's configuration does not necessarily yield the highest voltage or current gain.
2007-03-21 17:03:43 · answer #3 · answered by vrrJT3 6 · 1⤊ 1⤋
A common emitter amplifier takes its input at the base, and outputs at the collector.
A common collector amplifier takes its input at the base, and output is at the emitter.
A common base amplifier takes its input at the emitter and outputs at the collector.
2007-03-24 10:17:43 · answer #4 · answered by joshnya68 4 · 0⤊ 1⤋
Use emitter as ground, the amplifier has biggest gain.
2007-03-21 16:31:54 · answer #5 · answered by JAMES 4 · 1⤊ 0⤋
In this configuration, the signal is applied to the base and the output taken from the collector. The output will be inverted ( 180 degrees out of phase) with the input signal. This type of configuration is used mainly for voltage or power gain, and situations where a phase inversion is desired.
2007-03-21 18:51:43 · answer #6 · answered by scott p 6 · 0⤊ 0⤋