Derivation of fT And fMAX of a MOSFET

Slides:



Advertisements
Similar presentations
FET Small-Signal Analysis
Advertisements

Chapter 5: BJT AC Analysis. Copyright ©2009 by Pearson Education, Inc. Upper Saddle River, New Jersey All rights reserved. Electronic Devices and.
FET ( Field Effect Transistor)
Transistor Amplifiers
Frequency response I As the frequency of the processed signals increases, the effects of parasitic capacitance in (BJT/MOS) transistors start to manifest.
ECE 442 Power Electronics1 Bipolar Junction Transistors (BJT) NPNPNP.
Chapter 5 Bipolar Junction Transistors
Transistors These are three terminal devices, where the current or voltage at one terminal, the input terminal, controls the flow of current between the.
MOSFETs Monday 19 th September. MOSFETs Monday 19 th September In this presentation we will look at the following: State the main differences between.
Current Components inside Bipolar Junction Transistor (BJT) NPN BJT.
EE105 Fall 2007Lecture 4, Slide 1Prof. Liu, UC Berkeley Lecture 4 OUTLINE Bipolar Junction Transistor (BJT) – General considerations – Structure – Operation.
Department of EECS University of California, Berkeley EECS 105 Fall 2003, Lecture 19 Lecture 19: Frequency Response Prof. Niknejad.
Spring 2007EE130 Lecture 38, Slide 1 Lecture #38 OUTLINE The MOSFET: Bulk-charge theory Body effect parameter Channel length modulation parameter PMOSFET.
Department of EECS University of California, Berkeley EECS 105 Fall 2003, Lecture 14 Lecture 14: Bipolar Junction Transistors Prof. Niknejad.
COMSATS Institute of Information Technology Virtual campus Islamabad
ENE 311 Lecture 10.
09/16/2010© 2010 NTUST Today Course overview and information.
1 Frequency response I As the frequency of the processed signals increases, the effects of parasitic capacitance in (BJT/MOS) transistors start to manifest.
Chapter 17 Electronics Fundamentals Circuits, Devices and Applications - Floyd © Copyright 2007 Prentice-Hall Chapter 17.
Field-Effect Transistor
Bipolar Junction Transistor (BJT) Chapter March and 2 April 2014 Operation involves both electrons and holes, so is called “bipolar” Junction E-B.
المملكة العربية السعودية وزارة التعليم العالي - جامعة أم القرى كلية الهندسة و العمارة الإسلامية قسم الهندسة الكهربائية ELECTRONIC DEVICES K INGDOM.
FET ( Field Effect Transistor)
Part B-3 AMPLIFIERS: Small signal low frequency transistor amplifier circuits: h-parameter representation of a transistor, Analysis of single stage transistor.
Chapter (3) Transistors and Integrated Circuits B I P O L A R J U N C T I O N T R A N S I S T O R BJT in contrast to the "unipolar" FET Both minority and.
Unit II BJT Amplifiers.
An introduction to Junction Transistors. BITX20 bidirectional SSB transceiver.
SOGANG UNIVERSITY SOGANG UNIVERSITY. SEMICONDUCTOR DEVICE LAB. Bipolar Junction Transistor (1) SD Lab. SOGANG Univ. BYUNGSOO KIM.
Differential Amplifiers.  What is a Differential Amplifier ? Some Definitions and Symbols  Differential-mode input voltage, v ID, is the voltage difference.
BJTs. Transistor The transistor is the main building block “element” of electronics. A transistor is a semiconductor device used to amplify and switch.
Large Part Of This Lecture is Taken From Manipal Institute India
FREQUENCY ANALYSIS Determining capacitance and resistance for pole and zero.
JFET and MOSFET Amplifiers
Field Effect Transistors
Bipolar Junction Transistor (BJT). OUTLINE – General considerations – Structure – Operation in active mode – Large-signal model and I-V characteristics.
Bipolar Junction Transistor (BJT) Chapter and 25 March Operation involves both electrons and holes, so is called “bipolar” Junction E-B is forward.
CHAP3: MOS Field-Effect Transistors (MOSFETs)
TRANSISTOR - Introduction BIPOLAR JUNCTION TRANSISTOR (BJT)
Junction Field Effect Transistor
LARGE-SIGNAL BEHAVIOR OF BJTS Large-signal models in the forward-active region Effects of collector voltage in the forward-active region Ohmic and inverse.
CHAPTER 5 FIELD EFFECT TRANSISTORS(part a) (FETs).
ELCN 201 Analog & Digital Electronics Dr. Ahmed Nader Dr. Ahmed Hussein Fall 2013 Faculty of Engineering Cairo University 6/8/2016.
BJT Bipolar Junction Transistors (BJT) Presented by D.Satishkumar Asst. Professor, Electrical & Electronics Engineering
course Name: Semiconductors
COURSE NAME: SEMICONDUCTORS Course Code: PHYS 473 Week No. 9.
SILVER OAK COLLEGE OF ENGG. & TECHNOLOGY  SUB – Electronics devices & Circuits  Topic- JFET  Student name – Kirmani Sehrish  Enroll. No
BJT transistors FET ( Field Effect Transistor) 1. Unipolar device i. e. operation depends on only one type of charge carriers (h or e) 2. Voltage controlled.
CSE251 Lecture 8: Introduction to Bipolar Junction Transistor (BJT)
CHAPTER 10 AC Power Bipolar Junction Transistors: Operation, Circuit Models, and Applications.
Derivation of fT And fMAX of a MOSFET
Common Base and Common Collector Amplifiers
Lecture 4 Bipolar Junction Transistors (BJTs)
Lecture 10 Bipolar Junction Transistor (BJT)
Open book, open notes, bring a calculator
Derivation of fT And fMAX In Bipolar And MOSFETs
Bipolar Junction Transistor
Reading: Finish Chapter 12
Sung June Kim Chapter 10. BJT Fundamentals Sung June Kim
Small Signal High Frequency Transistor Amplifier Models
Bipolar Junction Transistor (BJT) Chapter and 25 March 2016
Analog Electronic Circuits 1
Electronics Fundamentals
B.Sc. (Semester -5) Subject: Physics Course: US05CPHY05 Analog Devices and Circuits UNIT-I FET and MOSFET.
Difference Between Voltage Amplifier and Power Amplifier
Lecture 4 OUTLINE Bipolar Junction Transistor (BJT)
Bipolar Junction Transistor (BJT) Chapter and 17 March 2017
Solid State Electronics ECE-1109
JFET Junction Field Effect Transistor.
Bipolar Junction Transistor (BJT) Chapter and 27 March 2019
Frequency response I As the frequency of the processed signals increases, the effects of parasitic capacitance in (BJT/MOS) transistors start to manifest.
Presentation transcript:

Derivation of fT And fMAX of a MOSFET

Derivation of fT (MOSFETs) The unity current gain frequency* (aka cutoff frequency) Defined under the condition that the output is loaded with an AC short. fT does not depend on Rg and ro

Derivation of fT (MOSFETs) (Continued) Assume the zero (sCgd) is smaller compared to gm.

fT with Parasitic RS and RD

Derivation of fT (MOSFETs) (Continued) (RS and RD are included) Miller’s Approximation

Derivation of fMAX (MOSFETs) fMAX * is the frequency at which the maximum power gain =1 (*aka maximum oscillation frequency) fMAX is defined with its input and output ports conjugate-matched for maximum power transfer So, we need to know the input and output impedance to define the input and output power as well as achieve the max power transfer matching condition.

Derivation of fMAX (MOSFETs) At high frequency (close to fmax), we can assume that So, Rg is independent of RL

Derivation of fMAX (MOSFETs) (Continued) Conjugate match at the input: Conjugate match at the output: For the matching conditions,

Power Gain (Under Conjugate Match) Using the definition of fT

Derivation of fMAX (MOSFETs)(Continued) (RS and RD are included) For high frequency condition, Cgs → short Hence, replace Rg by Rg+Rs w/ (RS+RD) term w/o (RS+RD) term

Derivation of fT And fMAX of a BJT

Derivation of fT (Bipolar) For Bipolar Transistors, CDE is due to minority carriers caused by FB

Derivation of fT (Bipolar) (Continued) QE = minority holes stored in emitter QB = minority electrons stored in base QBE = electrons induced by the current through the depletion region of BE-junction QBC = electrons induced by the current through the depletion region of BC-junction

Derivation of fT (Bipolar) (Continued) Width of Neutral Region Width of Depletion Region if drift current is considered. is greater than because of reverse-biasing.

Derivation of fT (Bipolar) (RS and RD are included) For bipolar, the result is similar. The only difference is that the term must be included.

Derivation of fMAX (Bipolar) For bipolar transistors, there is no term.