Zener Diode A zener diode is a p-n junction diode designed for stabilizing ( or regulating) i.e. keeping steady the output voltage of a d.c. power supply. Power supplies are needed to provide a d.c. output voltage for electronic circuits such as computers
FET AC Equivalent Circuit
G + Vgs _ S S gmVGS rd D
Control of ID by VGS is included as a current source gmVGS between the drain and the source. Input impedance represented by an open-circuit at the input terminals and the output impedance by the resistor
Junction Field-Effect Transistors (JFETs) Three-terminal semiconductor devices are far more useful than two-terminal devices. Used in applications ranging from signal amplifiers to the realization of logic and memory functions. Basic principle involved is
1.1.1 Drift and Diffusion Currents The two basic processes which cause electrons and holes to move in a semiconductor are: (a) drift, which is the movement caused by electric fields; and (b) diffusion, which is the flow caused by variations in the concent
SOLID STATE ELECTRONIC DEVICES
Dr. Leary Myers
Assessment: Course Test Laboratory Final Examination 20% 20% 60%
Laboratory Days and Times: Mondays & Wednesdays 1:00 p.m. to 5:00 p.m.
SOLID STATE ELECTRONIC DEVICES P24L
1. Introduction 2. S
1. (a) Why is the arrow on the bipolar junction transistor schematic symbol important? What are two of the factors associated with bias stability? When designing for the best bias stability which bias configuration should be chosen? (b) Consider the cir
1. (a) A plot of the collector current IC versus VCE of an npn Bipolar Junction Transistor (BJT), obtained from a curve tracer, shows IC increasing for increasing VCE in the active region. Briefly explain why this occurs. Also explain why the emitter of
DEPARTMENT OF PHYSICS P24L INCOURSE TEST TUESDAY, MARCH 8, 2005 - 11:00 a.m.
TIME : 1 Hour ANSWER ALL QUESTIONS 1.(a) Why are Field Effect Transistors considered unipolar transistors? 
State the two regions within which the JFET operates. Also writ
DEPARTMENT OF PHYSICS P24L INCOURSE TEST WEDNESDAY, MARCH 13, 2002 - 11:00 a.m. TIME : 1 Hour ANSWER ALL QUESTIONS
Briefly describe the difference between: (i) p-type and n-type semiconductors (ii) drift and diffusion currents Calculate the intrins
The Light-Emitting Diode (LED) The increasing use of digital displays in calculators, watches and all forms of instrumentation has contributed to the current extensive interest in structures that will emit light when properly biased. The two types in comm
(Vz is usually specified at the zener test current IZT, and is designated VZT.) Zener Equivalent Circuit The figures show the ideal and practical models of a zener diode in reverse breakdown.
It has a constant voltage drop equa
The p-channel MOSFET A p-channel enhancement-type MOSFET (PMOS transistor) fabricated on an ntype substrate with p+ regions for the drain and the source, has holes as charge carriers. The device operates in the same manner as the n-channel device except t
Metal Oxide Semiconductor Field Effect Transistors Recall that the bipolar junction transistor (BJT) is a current controlled device; that is the base current controls the amount of collector current. The FET is a voltage controlled device in which the vol
Bipolar Junction Transistor (BJT)
The (npn) BJT consists of three semiconductor regions: the emitter region (n-type), the base (p-type), and the collector region (n-type).
Metal contact Base (B) Metal contact
n-type Emitter region
Impatt and Trapatt diodes Impatt is an acronym based on the mechanism of its operation and is derivedfrom Impact Avalanche and Transit Time. Trapatt is derived from Trapped Plasma Avalanche and Triggered Transit. They are both junction diodes which are op
JFET circuits at DC Example 1.: Analyze the circuit below to determine the values of ID and VD given Vp = -4V and IDSS = 10mA.
VDD = 20 V ID RD = 1k VD
The gate is connected to the source which implies VGS = 0 We don not know whether the device is operati
1. Determine the equilibrium electron and hole concentration inside a uniformly doped sample of Si under the following conditions: a) T = 300 K, Na < Nd, Nd = 1015/cm3 b) T = 300 K, Nd < Na, Na = 1016/cm3 c) T = 300 K, Na = 9 x 1015 cm-3, Nd = 1016/cm3 (r
DC Analysis of Transistor Circuits Example 1. Analyze the circuit to determine all node voltages and branch currents given that VBE = 0.7V and = 100.
RC = 4.7k
4V RE = 3.3k
We observe that VB = 4V. Since VBE = VB VE , then VE = 4 0.7 = 3.3V. VE 0 And