Difference between revisions of "Test"
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====Push-Pull Follower==== |
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If we put two emitter followers together (npn transistor for positive |
If we put two emitter followers together (npn transistor for positive voltages; pnp transistor for negative voltages), we get a push-pull follower. |
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voltages; pnp transistor for negative voltages), we get a push-pull |
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follower. |
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[[Image:transistor_push_pull_follower.gif]] |
[[Image:transistor_push_pull_follower.gif]] |
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If <math>V_{in}</math> > 0.7V, then the current is amplified by the |
If <math>V_{in}</math> > 0.7V, then the current is amplified by the npn transistor. |
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npn transistor. |
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If <math>V_{in}</math> < -0.7V, then the current is amplified by the |
If <math>V_{in}</math> < -0.7V, then the current is amplified by the pnp transistor. |
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pnp transistor. |
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Beware that there is a |
Beware that there is a “dead band” when V<sub>in</sub> is between 0.7V and -0.7V, because the voltage has not pass the cutoff voltage for either transistor. This is known as '''crossover distortion'''. |
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and -0.7V, because the voltage has not pass the cutoff voltage for |
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either transistor. This is known as '''crossover distortion'''. |
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Revision as of 09:16, 19 August 2009
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Push-Pull Follower
If we put two emitter followers together (npn transistor for positive voltages; pnp transistor for negative voltages), we get a push-pull follower.
If > 0.7V, then the current is amplified by the npn transistor.
If < -0.7V, then the current is amplified by the pnp transistor.
Beware that there is a “dead band” when Vin is between 0.7V and -0.7V, because the voltage has not pass the cutoff voltage for either transistor. This is known as crossover distortion.
