How Does Cascading Common Emitter Transistors Affect Signal Amplification?

Click For Summary
SUMMARY

The discussion focuses on the amplification characteristics of cascading common emitter transistors in signal amplification circuits. Specifically, the output of the first common emitter transistor (Q1) is connected to the input of the second common emitter transistor (Q2). It is established that transistor 1 amplifies the input current from microamperes (uA) to milliamperes (mA), while transistor 2 further amplifies the output from transistor 1. The configuration includes a common-collector (emitter follower) and a common-base voltage amplifier, demonstrating a significant output increase from a 10 mV input to a 150 mV output.

PREREQUISITES
  • Understanding of common emitter transistor configurations
  • Knowledge of current amplification principles
  • Familiarity with common-collector and common-base amplifier concepts
  • Basic electronics and circuit analysis skills
NEXT STEPS
  • Study the characteristics of common emitter transistor amplifiers
  • Learn about the operation of common-collector (emitter follower) amplifiers
  • Explore common-base amplifier configurations and their applications
  • Investigate signal amplification techniques in multi-stage transistor circuits
USEFUL FOR

Electronics engineers, hobbyists designing amplifier circuits, and students studying transistor applications in signal processing will benefit from this discussion.

yy.toh
Messages
12
Reaction score
0
The ouput of common emitter transistor 1 is connected to input of common emitter transistor 2.
Please explain about the input and ouput signal (ac).
1.Is there any amplification after the transistor 1?
Normally the input is in uA, the output is in miliA
2.Is there any amplification after the transistor 2?
The output from transistor 1 is in miliA, how should it responsed by the transistor 2?
 
Engineering news on Phys.org
In the thumbnail, a 2-transistor common emitter (differential) amplifier is followed by an emitter follower (Q3). The first transistor (Q1) is a common-collector (emitter follower) current amplifier, and the second transistor (Q2) is a common-base voltage amplifier. A 10-mV input signal gives a 150 mV pulse out. Is this what you mean?

Bob S
 

Attachments

  • Diff_Amp_2A.jpg
    Diff_Amp_2A.jpg
    30.4 KB · Views: 524
Last edited:

Similar threads

Understanding the base emitter voltage in a common emitter NPN BJT
  • · Replies 16 ·
Replies
16
Views
11K
Class A Amplifier Sinusoidal Input/Output Relation
  • · Replies 3 ·
Replies
3
Views
4K
Some basic doubts regarding transistors characteristics
  • · Replies 7 ·
Replies
7
Views
6K
BJT transistor analysis: common emitter confusion
  • · Replies 5 ·
Replies
5
Views
3K
Switching scheme in an inverter
  • · Replies 18 ·
Replies
18
Views
3K
How BJT transistor works (with conventional current notation perspective)
  • · Replies 19 ·
Replies
19
Views
7K
Learn Transistor Setup & Common Emitter Setup
  • · Replies 12 ·
Replies
12
Views
3K
How Can I Operate a Japan Servo AS27278 Motor?
  • · Replies 1 ·
Replies
1
Views
2K
How a cascaded common emitter transistor amplifier is modelled
  • · Replies 4 ·
Replies
4
Views
7K
How does a NAND gate work using transistors?
  • · Replies 1 ·
Replies
1
Views
2K