Direct Coupled CE Amplifier

Direct Coupled CE amplifier

Direct Coupled amplifier using transistors. The ouput signal of first stage is directly connected to the input of the next stage. This direct couplig allows the quiescent d.c. Collector current of first stage to pass through base of the next stage, affecting its biasing conditions.
Due to absence of RC components, its low frequency response is good but at higher frequencies shunting capacitors such as stray capacitances reduse the gain of the amplifier
The transistor parameter such as Vbe and β change with temperature causing the collector current and voltage to change. Because of direct coupling these changes appear at the base of the next stage, and hence in the output. Such an unwanted change in the output is called Drift and it is serious problem in the direct Coupled amplifiers.

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