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Practical Electronics/Amplifiers/Common emitter
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Transistor - Common_Emitter_amplifier
thumb|200px|Common Emitter Amplifier
Image:Common_emitter_amplifier.svg
QUALITATIVE CHARACTERISTICS
Current Gain: ..... HIGH
Voltage Gain: ..... HIGH
Power Gain: ..... HIGH
Input Impedance: ... AVERAGE
Output Impedance:... AVERAGE
QUANTITATIVE CHARACTERISTICS
Input Resistance(base): Zb=β×re'
-> β: Current Gain (Ic/Ib), where 'Ic' is Colector DC current and 'Ib' is DC Base current;
-> re': Base-Emitter (Ut/Ie), where Ut is thermal voltage(≈25mV at 25°C) and
'Ie' is DC emitter current;
Input Resistance(general): Zg= Zb || R1 || R2, where R1 and R2 are the same as the picture above.