• If a transistor is used as the
active element of the amplifier stage, the output of the
feedback network is loaded
appreciably by the relatively low input resistance
( hie) of the transistor.
• An emitter – follower input
stage followed by a common emitter amplifier stage
could be used.If a single
transistor stage is desired, the use of voltage – shunt
feedback is more suitable. Here,
the feedback signal is coupled through the
feedback resistor R’ in series
with the amplifier stage input resistance ( Ri).
f = (1/2pRC)[1/Ö 6 + 4(RC / R)]
hfe > 23 + 29 (R/RC) + 4 (RC / R)
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