Ecircuit Final notes PDF

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Summary

Review of all the material that will be covered on the final exam for Dr Allen Turner...

Description

Part 1: 

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Electric Field o In the same direction as current (- to +) o Increasing EF, increases force and velocity o Force in the same direction as EF Electron Concentration o Increasing EC, increases likelihood of holes being filled (more electros) o Adding impurities increase eo Increasing EC, decreases mobility o As carrier concentration increases, temperature goes up, mobility goes down, conductivity increases and resistance decreases Other o Impure semiconductor: temperature independent PN junction: o Diffusion:  the process of random thermal motion moving from a high concentration to low concentration until you reach a uniform distribution  diffusion for holes go from left to right in PN junction o Net charge is neutral, same number of electrons as protons o EF will be at the peak at the boundary of N and P type o As depletion region expands, rate of diffusion decreases o Forward voltage:  EF becomes smaller  Depletion region becomes smaller  Diffusion current goes up, reverse saturation goes down o Recombination of e- release energy and when enough energy is released, it releases light. o Breakdown:  EF increases which causes kinetic energy to increase  As the kinetic energy creates the energy needed for breakdown, the impact of collision generates e-/hole pairs  1. Impact ionization  2. Quantum mechanical tunneling

Diodes: 

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Ideal conditions o Id vs Vd Graph o Vin vs Vout graph Draw diode and NP condition Half wave vs Full wave rectifier Diode with capacitor o The bigger the cap, the smaller the ripple time, the better the output voltage Zener

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Clippers o Clips the amplitude based on the voltage supply. o Clampers Wave shapers o Use nodal to find slope/ VO equation How are bjts and mosfets different o BJT: current controlled o MOSFET: voltage controlled

Op amp 

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Problems: o Gain Bandwidth Product:  General problem with high gain amplifiers is oscillations  Tradeoff between gain and bandwidth o Slew rate  If output cant change faster than slew rate, it cannot change instanty o Base bias currrents Positive feedback o Two outputs, + or – o Hysteresis: retaining original value o MOSFET BJT Concept on power supplies...