ELEG 3214 Lecture 4: CH2 OP-AMPS CLOSED LOOP INVERTING / NON IDEAL CLOSED LOOP GAIN / SOLVING THE LOW INPUT RESISTANCE ISSUE

• School: University of Arkansas
• Department: Electrical Engineering
• Course: ELEG 3214
• Professor: Omar Manasreh

Document Summary

Lec 4 8-31-16 ch2 op-amps / closed loop inverting / Non ideal closed loop gain / solving the low. Terminals 1 and 2 make a virtual short. This means that their voltages are roughly the same but don"t actually physically touch each other to make an actual short. An ideal op-amp assumes the voltages are exactly the same. The op amp is designed to multiply the difference between the two voltages applied at terminals 1 and 2 by a and output this new voltage value. V1 is subtracted from v2 because v1 goes into the negative input terminal (inverting terminal, distinguished by the + and - signs) They are used with external circuitry, usually resistors and capacitors. Ideal op amps assume no current flows into the input terminals of the op amp and instead goes around the op amp through the external circuitry. A gain refers to internal gain of the actual op amp (also called open loop gain).