10 Short Circuit Protection or Overload Protection A simple short circuit protection
or overload protection can be provided by using a resistance and the two diodes .
The circuit is shown in the Fig . 9 . 25 . Figure 9 . 25 Short circuit protection ...
Author: U.A.Bakshi A.P.Godse
Publisher: Technical Publications
Diode ApplicationsVoltage multiplier circuits : Working and comparison of voltage doubler, tripler and voltage quadrupler configurations. Limitations of voltage multiplier circuits. Effect of frequency on load regulation.Clipping and clamping circuits : Series and parallel forms of clipping circuits, Biased clipper, their operation and transfer characteristics. Clamping circuits.MOSFET ApplicationsMOSFET in VLSI : V-I characteristic equation in terms of W/L ratio, MOSFET scaling and small geometry effects, MOSFET capacitances. Modeling MOS transistors using SPICE, CMOS inverter, Static characteristics - Noise margin, threshold voltage, Layout and latch-up prevention, Other logic gates - NAND and NOR gates. Objective : To study Power MOSFET and Power BJT devices and their data sheet specifications.Power MOSFETConstruction - Lateral double diffused MOSFET, VMOSFET. Drive requirements, Comparison with power BJT. One example of drive circuit for POWER MOSFET.Power BJTPower BJT construction, Data sheet specifications, Thermal resistance, Second breakdown, Safe operating area (SOA), Thermal runaway, BJT as a switch in display and relay drive applications, Drive considerations, Anti saturation circuits, Comparison with POWER MOSFET.Large signal AF BJT amplifiersBlock schematic of AF amplifier. Classes of power amplifiers - Class A, Class B, Class AB. An overview and applications of Class C and Class D amplifiers. Class A with resistive load, Transformer coupled class A amplifier, Class B Push-pull, Class AB, Complementary symmetry and Quasi-complementary configurations. Efficiency analysis for Class A transformer coupled amplifier, Class B push-pull amplifiers. Comparison of efficiencies of other configurations. Distortions in amplifiers, concept of Total Harmonic Distortion (THD).High frequency, small signal BJT amplifiersBehavior of transistor at high frequencies. Modified T equivalent circuit. High frequency hybrid CE amplifier model. CE short circuit current gains for T and hybrid models. Definitions and derivations for , and . Amplifier bandwidth taking into account source and load resistances. Techniques to improve bandwidth. Single tuned, Double tuned and stagger tuned amplifiers. Unloaded and loaded Q. Effect of staggering on bandwidth (no derivations).Feedback amplifiers and oscillatorsConcept of feedback. Negative and positive feedback. Classification of amplifiers based on feedback topology. (Voltage, Current, Transconductance and Transresistance amplifiers). Transfer gain with feedback. Advantages and disadvantages of negative feedback. Effect of feedback on input and output impedances and bandwidth of an amplifier. Analysis of one circuit for each feedback topology.OscillatorsOscillator startup mechanism, need for amplitude limiting. Study of following oscillator circuits (using FET) - (Derivations not expected) - LC oscillators - General form of LC oscillator. Hartley oscillator, Colpitts oscillator, Clapp oscillator. Crystal oscillator, Crystal clock.Linear voltage regulators and voltage referencesBlock schematic of linear regulators. Emitter follower regulator, Transistor series regulator and its analysis for performance parameters. 3 terminal floating, dual and adjustable regulators. Method of boosting output current using external series pass transistor. Performance parameters - Load and Line regulation, Ripple rejection, Output resistance and efficiency. Protection circuits - Reverse polarity protection, over current, fold back current limiting, over voltage protections. Important data sheet specifications of linear regulators. Voltage references, their peculiarities and applications.