Introduction to amplifiers
Electronic circuits are for amplifying an electrical signal.
What are the electronic amplifiers?
An electronic circuit with a base in the input and a collector in the output circuit, and the emitter is common.
What is the amplifier in the common emitter junction?
The input of an amplifier is equal to the dynamic input resistance of the transistor.
What is the input dynamic resistance of an amplifier equal to?
The dependence of output signal amplitude on input frequency.
What is the amplitude-frequency characteristic?
It has high input impedance and low output impedance.
What is the basic characteristic of the common-collector configuration?
Time-varying voltages and currents.
What are electrical signals?
Amplifier in common emitter junction.
Which amplifier is the amplifier with the highest current and voltage gain?
The action of the amplifier's output stage on the input stage. A portion of the output signal is fed back through the feedback branch and affects the input signal.
What is feedback?
Excite the system with different frequencies and measure the output amplitude.
How is the amplitude-frequency characteristic measured?
It’s called an emitter follower, used for impedance matching.
What is another name for the common-collector, and what is its purpose?
The difference is that DC amplifies both DC and AC signals, while AC amplifies only AC signals.
What is the difference between DC amplifiers and AC amplifiers?
The operating point is placed in the normal active area.
How is the operating point set for the transistor to work as an amplifier?
Re≫Rb/B.
What is the condition for stability?
The range of frequencies the system can transmit signals through.
What is bandwidth?
The input and output signals are in phase.
Is there a phase shift between the input and output?
Gains are the ratios of identical output and input values. It is expressed in decibels.
What is the gain of the amplifier and how is it expressed?
It shows how the collector voltage and the position of the static operating point will change.
What does the static work direction show?
An amplifier is equal to the parallel combination of the dynamic output resistance of the transistor.
What is the output resistance of an amplifier equal to?
Filtering analysis, control, and circuit optimization.
What are the applications of the amplitude-frequency characteristic?
The voltage gain is approximately equal to 1.
What is the voltage gain in the common-collector configuration?
The operation of the amplifier was analyzed only for DC voltages and currents.
What is static analysis?
Ap =Au * Ai
What is power amplifier formula?
Connecting a resistor in the emitter circuit achieves the stability of the static operating point, so that the collector current and emitter voltage do not depend on the transistor's parameters and temperature.
What is achieved by connecting a resistor in the emitter circuit?
A graph with frequency on the horizontal axis and amplitude on the vertical.
How is the amplitude-frequency characteristic displayed?
It stabilizes the transistor and reduces nonlinear distortions.
What is the purpose of the emitter resistor?