Op amps

synonyms: operational amplifiers, op-amps

A part of a circuit used to amplify the voltage coming in. Utilizes a small voltage difference between its inputs to create a large voltage in its output.

Operates on gain - a multiplier for input voltage difference.

Usually we use a feedback loop connecting V_out to the inverting feedback loop to set them to being equal. Then any change in the not inverting input will change V_out accordingly.

Such a small difference between the inputs leads to the following: $V_{inverted}=V_{non-inverted}$

High input impedence | Low output impedence

Op amp questions:

Rules:

1. Essentially no current flows in or out of the inputs
2. Op amp tries to keep the voltage of the inputs the same (only applies when we use a feedback loop)
3. HUGE gain

Inverting amplifier

Voltage source going into the negative terminal. $G=-R_2/R_1$

Non-inverting amplifier

Voltage source is going into the positive terminal. $G=1+R_2/R_1$