EC1202 ELECTRON DEVICES

ANNA UNIVERSITY CHENNAI :: CHENNAI 600 025
CURRICULUM 2004
B.E. ELECTRONICS AND COMMUNICATION ENGINEERING
EC1202 ELECTRON DEVICES

AIM
The aim of this course is to familiarize the student with the principle of operation, capabilities and limitation of various electron devices so that he will be able to use these devices effectively.

OBJECTIVE
On completion of this course the student will understand

• The basics of electron motion in electric field and magnetic field
• Mechanisms of current flow in semi-conductors
• Diode operation and switching characteristics
• Operation of BJT, FET, MOSFET metal semiconductor rectifying and ohmic contacts and power control devices.

UNIT I ELECTRON BALLISTICS AND INTRINSIC SEMICONDUCTORS 9
Force on charge in electric field – Motion of Charge in uniform and time varying electric fields – Force on a moving charge in a magnetic field – calculation of cyclotron frequency – calculation of electrostatic and magnetic deflection sensitivity.
Energy band structure of conductors, semiconductors and insulators – Density distribution of available energy states in semiconductors – Fermi- Diac probability distribution function at different temperatures – Thermal generation of carriers – Calculation of electron and hole densities in intrinsic semiconductors – Intrinsic concentration – Mass Action Law.

UNIT II EXTRINSIC SEMICONDUCTOR AND PN JUNCTIONS 9

N and P type semiconductors and their energy band structures – Law of electrical neutrality – Calculation of location of Fermi level and free electron and hole densities in extrinsic semiconductors – Mobility, drift current and conductivity – Diffusion current – Continuity equation - Hall effect.
Band structure of PN Junction – Current Component in a PN Junction – Derivation of diode equation – Temperature dependence of diode characteristics.

UNIT III SWITCHING CHARACTERISTICS OF PN JUNCTION AND SPECIAL DIODES 9
Calculation of transition and diffusion capacitance – Varactor diode – charge control description of diode – switching characteristics of diode – Mechanism of avalanche and Zener breakdown – Temperature dependence of breakdown voltages – Backward diode – Tunneling effect in thin barriers Tunnel diode – Photo diode – Light emitting diodes.

UNIT IV BIPOLAR JUNCTION TRANSISTORS AND FIELD EFFECT TRANSISTORS 9
Construction of PNP and NPN transistors – BJT current components – Emitter to collector and base to collector current gains – Base width modulation CB and CE characteristics – Breakdown characteristics – Ebers – Moll model – Transistor switching times.
Construction and Characteristics of JFET – Relation between Pinch off Voltage and drain current – Derivation. MOSFETS – Enhancement and depletion types.

UNIT V METAL SEMICONDUCTOR CONTACTS AND POWER CONTROL DEVICES 9
Metal Semiconductor Contacts - Energy band diagram of metal semiconductor junction Schottky diode and ohmic contacts.
Power control devices: Characteristics and equivalent circuit of UJT - intrinsic stand off ratio. PNPN diode – Two transistor model, SCR, Triac, Diac.

TUTORIAL 15

TOTAL : 60
TEXT BOOK

• Jacob Millman & Christos C.Halkias, “Electronic Devices and Circuits” Tata McGraw–Hill, 1991 .

REFERENCES

• Nandita Das Gupta and Amitava Das Gupta, Semiconductor Devices – Modelling and Technology, Prentice Hall of India, 2004.
• Donald A.Neaman,” Semiconductor Physics and Devices” 3rd Ed., Tata McGraw-Hill 2002.
• S.Salivahanan, N.Sureshkumar and A.Vallavaraj, Electronic Devices and Circuits, TMH, 1998.
• S.M.Sze, Semiconductor Devices – Physics and Technology, 2nd edn. John Wiley, 2002.
• Ben G.Streetman and Sanjay Banerjee, Solid State Electronic Devices, Pearson Education 2000.

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