전자회로 개요 기초 이론 Diode Transistor (MOSFET, BJT) 전자회로 1 Differential Amplifier Frequency response Feed back Operational amplifier Digital circuit (Logic, Memory, …) Analog circuit Filters & tuned amplifier Oscillator Power amplifier 전자회로 1 전자회로 2

Two port network parameters

Admittance parameters Two port network The network contains No independent sources Admittance parameter

Measurement of Y-parameters The computation of the parameters follows directly from the definition + + - -

Example Find the admittance parameters for the network Next we show one use of this model

An application of the admittance parameters Determine the current through the 4 Ohm resistor The model plus the conditions at the ports are sufficient to determine the other variables.

Impedance parameters + + + - + - - -

Example Find the Z parameters Write the loop equations Rearranging,

hybrid parameter + + - - + + - -

Transmission(ABCD) parameter + + - -

Cascade of networks + + + - - - + + - -

Example Determine the transmission parameters

Cascade of networks

MOSFET

MOSFET 구조 Insulator: Silicon dioxide or Polysilicon Substrate: Single crystal silicon wafer Gate: Electrode

Channel Induced with Positive Gate-Source Voltage

MOS operation : no Drain-Source bias (1) Gate전압이 없을 때 pn-np diode 두 개가 붙어 있는 형태이어서 전류의 흐름이 없다. (2) Gate에 약간의 (+)전압을 가해주면 p-type 반도체에 있던 hole들이 멀리 밀려나고, gate 주변은 depletion영역으로 된다.

MOS operation : with Drain-Source bias (3) (4) 전하 전기장 전압 전자 흐름 에너지 band

(3) Gate역할 drain source

Large signal equivalent Equivalent circuit Early effect

Small signal equivalent

Bias point + small signal equivalent DC bias point : +

Small signal parameter extraction

Equivalent circuits of MOSFET

Bipolar Junction transistor Heater cathode grid anode 진공관(3극관)과 동작원리 같음.

Equivalent circuits of BJT

MOSFET equivalent circuit : Admittance parameter

Admittance-to-ABCD parameter transform

Amplifier spec. from ABCD parameters output impedance Signal source input impedance Load resistance (1) Voltage gain (2) Current gain (3) Input impedance (4) Output impedance

The three basic MOSFET amplifier configurations.

Network parameter for basic MOS amplifiers Common source amplifier Common gate amplifier

Network parameter for basic amplifiers Common drain amplifier

Amplifier parameter for basic MOSFET amplifiers Type Voltage gain Input impedance Output impedance Common source Common gate Common drain

The three basic BJT amplifier configurations.

Network parameter for basic BJT amplifiers Common emitter amplifier Common base amplifier

Common collector amplifier

Amplifier parameter for basic BJT amplifiers Type Voltage gain Input impedance Output impedance Common emitter Common base Common collector

Ideal voltage amplifier 입력 임피던스 : 무한대 출력 임피던스 : 0 Signal source (input impedance) (Output impedance) Load Output impedance input impedance + + - - Voltage gain Feed back ratio → 0

Ideal current amplifier 입력 임피던스 : 0 출력 임피던스 : 무한대 Signal source (input impedance) (Output impedance) Load Output impedance input impedance + + - - Current gain Feed back ratio → 0

Series of unilateral amplifiers (zero feed-back) Signal source Load + + + - - -