Amplifiers
The operational amplifier is the building block of analog electronics.
What is an operational amplifier?
Exercise — realistic opamp model
Exercise — non-inverting opamp
Special topics in AC analysis $\qquad$ Semiconductors
Further study
One of the best sources of information about analog circuit design and operational amplifiers is the design library at Analog Devices. This company is one of the leaders in analog integrated circuits. Over the years their design engineers have written great tutorials and detailed guides about their product line and, more importantly, about the fundamentals of analog design and signal sensing. This is a highly trusted source.