Tutorials / Amplifiers and Filtering
Cascode Amplifiers 
Two-transistor combinations, such as the Darlington configuration, provide advantages over single-transistor amplifier stages...
A Designer's Guide to Instrumentation Amplifiers
Instrumentation amplifiers (in-amps) are sometimes misunderstood. Not all amplifiers used in instrumentation applications are instrumentation amplifiers, and by no means are all in-amps used only in instrumentation applications...
Auto-Zero Amplifiers
Whenever the subject of auto-zero or chopper-stabilized amplifiers comes up, the inevitable first question is “How do they really work?”...
Elliptical Filters
Frequency- selective networks are useful for suppressing noise, rejecting unwanted signals, or in some way manipulating the input signal’s characteristics...
Logarithmic Amplifiers
The design and use of logarithmic/exponential circuits are often associated with involved temperature compensation requirements and difficult to stabilize feedback loops. For these considerations and others...
Sallen-Key Filter Design
The report gives a general overview and derivation of the transfer function, followed by detailed discussions of low-pass and high-pass filters, including design information, and ideal and non-ideal operation...
Current Feedback Amplifiers
The majority of op amp circuits are closed-loop feedback systems that implement classical control theory analysis. Analog designers are comfortable with Voltage FeedBack (VFB) op amps in a closed-loop system and are familiar with the ideal op amp approximations feedback permit...
Difference Amplifiers
In an era of discrete tube or transistor op-amp modules, any potential advantage to be gained from fully-differential circuitry was masked by primitive op-amp module performance...
Filters for Digital Communications
The process of filtering an analog signal removes all frequencies above or below a corner frequency, passing only a band of frequencies, or rejecting a band of frequencies. When digital signals are filtered...