Electronic
Devices and Circuits
Engineering
Sciences 154 |

Amplifier Symbols |
Amplifier Equivalent Circuit |

Miscellaneous amplifier references:The quest for the ideal rf amplifierExamples of high performance rf amplifierAmplifier Basics

The importance of input and output impedance:

Therefore, in most instances, we require than

and

or we can say that high input impedance and low output is a desirable quality in most amplifiers!

Typical Frequency Response:

Amplifier Distortion:

Feedback in Amplifier Circuits:

Notice that

What's so great about feedback?Gain Desensitivity:

Bandwidth Extension:

(see Decibel Measure and Asymptotic Bode Plots and Decibel Measure and Asymptotic Bode Plots for two nice Bode plot references)

Suppose- See corresponding Bode plotWith feedbacks

so that with feedback - See corresponding Bode plotDistortion Reduction:

If you were to put the nonlinear input/output response (gain curve) illustrated above into the closed-loop gain expression, you would find:

Operational Amplifiers - Op Amps:For a valuable reference on op amps see the Texas Instruments "White paper" Understanding Operational Amplifier Specifications by Jim Karki

Another two nice references on op amps can seen at Operational Amplifiers (source) and at Op Amp Basics (Also see Bowden's Hobby Circuits)

A discussion of Op Amp Filter Circuits

Last updated April 23, 2010