ELEC 350 Electronics I Fall 2011Review Topics for Exam #2The following is a list of topics that could appear in one form or another on the exam. Not all of these topics will be covered, and it is possible that an exam problem could cover a detail not specifically listed here. However, this list has been made as comprehensive as possible. You should be familiar with the topics on the previous review sheet in addition to those listed below.Semiconductors- holes and electrons- acceptor and donor impurities (group III and V elements on the periodic chart)- n-type vs. p-type material- free charges vs. immobile charges (ion cores)- depletion region and the built-in field- diffusion and drift currentpn-junction diode operation- basic construction- diode symbol and correct orientation- forward and reverse bias- the diode equation and its approximations (PWL models)- saturation current (Is), emission coefficient (n), thermal voltage (VT)- i-v characteristic (and orientation of iD and vD)- graphical and iterative analyses of diode circuits (load lines)Peak Inverse Voltage (PIV)Piecewise linear (PWL) diode models (for both pn-junction and Zener types)- turn-on (VD or VF) and zener (VZ or VZ0) voltages- forward (rd) and zener (rz) resistances- dependence of forward resistance on avg. (DC) diode current (rd = nVT / ID)Rectifier circuits- half-wave rectifiers- full-wave rectifiers- pulsating DC and its average value- effect of diode voltage drop(s) on output of a rectifier- filter capacitor selection vs. load resistance and/or load current(VP = peak value of output voltage, Vr = ripple voltage) rLPrLVfiVVRfCmaxmin1 (half-wave rectifier) rLPrLVfiVVRfC221maxmin (full-wave rectifier)- transformer secondary voltage selection (peak vs. rms)- ripple voltage- percentage ripple- PIV ratings of diodes- voltage doubler circuits- peak diode current (VP = peak value of output voltage, Vr = ripple voltage) rPLDVVIi 221max (half-wave rectifier) rPLDVVIi 221max (full-wave rectifier)Zener diodes- i-v characteristic- zener voltage- reverse breakdown region- PWL model (steep slope in rev. breakdown region leads to relatively small rz)- max. power rating and max. safe current; min. current for effective operationVoltage Regulation- design of simple zener diode regulators- advantages with regard to ripple voltage- selection of minimum zener current- maximum power dissipation rating- selection of filter capacitors in zener regulator circuits- relationship of power rating to max. load current (iLmax < 0.45Pzmax/VZ)Schottkey barrier diodeVaractor diode (or voltage variable capacitor)Metal-oxide varistor (MOV) – typically used as protection against AC line voltage spikesDiode-based attenuator circuits- separate DC and AC analyses based on principle of superposition- DC voltage and current levels much higher than AC levels- AC fluctuations are a negligible fraction of DC levels so that rd does not vary significantly- design path: pick attenuation → rd value(s) → ID value(s) → bias resistor value(s)- foundational relationship: DTdInVr , where ID is the DC current; neglect AC component- typically employ DC blocking/AC passing capacitors and AC blocking/DC passing inductorsRelevant course material: HW: #4#5Labs: #5-#8Textbook: Chaps. 3 and 4 (light on Sec. 4.6)Lecture notes: (none)Web Links: (none)Mathcad: (none)Matlab: