Class A Power amplifiers(series fed)
An amplifier is of type class A if its output remain in the active region during a complete cycle of sine wave input signal .It is an amplifier under normal condition i.e the output never saturates or cut off.If the input is 360°,then output is also 360° ,i.e distortion is very low
Efficiency
\( V_{pp}=V_{cc}\)
\( I_{pp}=\frac{V_{cc}}{R_c}\)
\( I_c=\frac{V_{cc}}{2R_c}\)
\(η =\frac{V_{pp}I_{pp}}{8V_{cc}I_c}\)
\(=\frac{V_{cc}\frac{V_{cc}}{R_c}}{8V_{cc}\frac{V_{cc}}{2R_c}}\)
\( =\frac{1}{4}\)=25%
η is low .So class A is never used as a power amplifierMathJax example
An amplifier is of type class A if its output remain in the active region during a complete cycle of sine wave input signal .It is an amplifier under normal condition i.e the output never saturates or cut off.If the input is 360°,then output is also 360° ,i.e distortion is very low
Efficiency
\( V_{pp}=V_{cc}\)
\( I_{pp}=\frac{V_{cc}}{R_c}\)
\( I_c=\frac{V_{cc}}{2R_c}\)
\(η =\frac{V_{pp}I_{pp}}{8V_{cc}I_c}\)
\(=\frac{V_{cc}\frac{V_{cc}}{R_c}}{8V_{cc}\frac{V_{cc}}{2R_c}}\)
\( =\frac{1}{4}\)=25%
η is low .So class A is never used as a power amplifier
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