1. The operational amplifier
A basic building block in many electrical circuits
First used to implement mathematical operations (addition, integration, etc.)
Also called the op amp

2. Op amp
Eight-lead DIP package

3. Op amp, cont.
Circuit symbol

4. Op amp, cont.
Terminal voltage and currents

5. Op amp, cont.
The output voltage is a function of the input voltage difference
Linear region: vo = A (vp - vn)
A ≥ 104

6. Op amp, cont. Idealized operational amplifier A -> ∞ -> vn = vp
Input resistance -> ∞ > in = ip = 0
Note: in + ip + io + i1 + i2 = 0
io = - i1 - i2

7. Inverting amplifier

8. Inverting amplifier, cont.

9. Classwork #2
Find vo