The Op Amp Page
(**SPECIAL NOTE FOR FINAL PROJECT: IF you want to use an op amp with Vcc and Ground as we did in the labs, use the LM324. If you want to use one with +Vcc and -Vcc use them LF353)
Here is 'everything you need to know' about op amps. Why do we love them so much?
1) We can build a huge variety of extremely useful circuits with them including amplifiers, buffers, inverters, etc.
2) We can use them to isolate input and output circuits. Since the current going in to the op amp =0, the input circuit can be set up so it does not have to 'source' any current (often it can't or shouldn't). The current for the output circuit comes from the POWER SUPPLY for the op amp, rather than from the input circuit. The voltage follower/buffer below works on this principle.
Lectures:
Lecture (4-1) Op-Amp Characteristics
Lecture (4-2) Negative Feedback
Lecture (4-3) Ideal Op-Amp Model and Non-Inverting Amplifier
Lecture (4-4) Inverting Amplifier
Lecture (4-5) Summing Amplifier
Lecture (4-6) Difference Amplifier
Lecture (4-7) Voltage Follower
Cookbooks (quick-notes):
Op Amp Cookbook -- Recognizing Inv & NonInv Amps.docx
Op Amp Cookbook -- Recognizing Inv & NonInv Amps ANSWERS.docx
What you need to know about an ideal op amp:
a) with feedback: Vp=Vn and input currents =0.
b) without feedback Vo = A(vp-vn) where A is so large that Vo 'rails' between +Vcc and -Vcc (op amp used as switch below, uses that principle)
c) for all cases -Vcc < Vo < Vcc (op amp 'rails out' at (cannot go above or below) power supply voltages)
Quick Video Summaries of common op amp circuits:
(Power Point to take notes on)
Op Amp as Switch:
http://www.youtube.com/watch?v=i1Ol7JpH-Sw
Non-Inverting Amplifier:
http://www.youtube.com/watch?v=CfORgEU-hFM
Op Amp non inv op amp problems.docx
Op Amp non inv op amp problems solutions.pdf
Inverting Amplifier:
http://www.youtube.com/watch?v=vjIxw6I1NF8
Op Amp inv op amp problems.docx
Op Amp inv op amp problems solutions.pdf
Non-Inverting Summer (adder):
http://www.youtube.com/watch?v=u8RjjRIC8hY
Inverting Summer (adder):
http://www.youtube.com/watch?v=cTN-w6_HzgI
Differencing (subtracting) amplifier:
http://www.youtube.com/watch?v=O8nSDOG9MDo
Voltage Follower:
http://www.youtube.com/watch?v=ScNFmIPZQxQ
Designing Op Amp Circuits:
Here is the original deck of cards I used in class:deck of cards print.pptx
You might find this one even easier to use (block diagrams shown via math symbols) deck of cards op amps version B.pptx
Rin,Rout for Op Amps (also adding DC offsets to op amp circuits) Rin,Rout and VDC for op amps.pdf
Labs:
Lab 3 - R2R Ladder for Digital to Analog Conversion (DAC) (using the op amp as non-inverting amplifier) See also OpAmp DtoA conversion.pdf
Lab 5 - Resistive Sensors (using the op amp as a switch, and also (extra credit) an inverting amplifier)
Intro to Op Amps, How they Work, and how the pins are laid out
http://www.youtube.com/watch?v=5my9_kRYVqc&list=PL170A01159D42313D&index=11&feature=plpp_video
Examples: Review For Midterm Ii
Identifying common op amp circuits:
Op Amp Cookbook -- Recognizing Inv & NonInv Amps.docx
Op Amp Cookbook -- Recognizing Inv & NonInv Amps ANSWERS.docx
Analysis of op amp circuits:
OpAmp (diff amp) Node Voltage Example.pdf
OpAmp (inv amp) Thevenin example.pdf
OpAmp (resistance bridge) Thevenin Example.pdf
Design examples (common op amp circuits):
OpAmp Design examples (amp & summer).pdf
Design examples (cascaded op amps):
OpAmp Linear Algebraic example 1.pdf
OpAmp Linear Algebraic example 2.pdf
OpAmp Linear Algebraic example 3.pdf
OpAmp Linear Algebraic example 4.pdf