Electronic Devices and Circuits: Unit V: Power Amplifiers and DC/DC Converters
Classification of Power Amplifiers
Amplifier classes represent the amount of output signal variation over one cycle of operation when excited by a sinusoidal input signal.
CLASSIFICATION OF POWER AMPLIFIERS
Classes of Amplifiers
Amplifier
classes represent the amount of output signal variation over one cycle of
operation when excited by a sinusoidal input signal.
Output Stages of Power Amplifier
Output
stages are classified based on the resulting collector current waveform when an
input signal is applied.
Class A Amplifier
In
Fig. 5.3 (a),
i.
Current IC is greater than amplitude of signal current 
ii.
Transistor conducts for entire cycle of input signal.
iii.
Conduction angle is 360°.
Class B Amplifier
In
Fig. 5.3 (b)
i.
Biased as zero dc current
ii.
Transistor conducts for only half the cycle of input signal
iii.
Conduction angle is 180°
Class AB Amplifier
In
Fig. 5.3 (c)
i.
The transistor is biased at a nonzero dc current much smaller than peak current
of the sine wave signal.
ii.
Conducts for an interval slightly greater than half a cycle.
iii. Conduction angle is greater than 180° but less than 360°
Class C Amplifier
i.
Transistor conducts for an interval shorter than half a cycle.
ii.
Conduction angle is less than 180°.
Electronic Devices and Circuits: Unit V: Power Amplifiers and DC/DC Converters : Tag: : - Classification of Power Amplifiers
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Electronic Devices and Circuits
EC3353 - EDC - 3rd Semester - ECE Dept - 2021 Regulation | 3rd Semester ECE Dept 2021 Regulation