tailieunhanh - Circuits & Electronics P7

Incremental Analysis Fall 2000 Lecture 7 1 .Review Nonlinear Analysis Analytical method Graphical method Today Incremental analysis Reading: Section Fall 2000 Lecture 7 2 .Method 3: Incremental Analysis Motivation: music over a light beam Can we pull this off? iD iR vI (t ) + – + vD LED light intensity I D ∝ iD vI music signal AMP iR ∝ I R light intensity IR in photoreceiver LED: Light Emitting expoDweep ☺ t vI (t ) iD (t ) light iR (t ) sound nonlinear Fall 2000 linear problem! will result in distortion Lecture 7 3 .Problem: The LED is nonlinear iD distortion iD t vD t vD vD = vI iD vD t Fall 2000 Lecture 7 4 .Insight: ID iD small region looks linear (about VD , ID) VD vD DC offset or DC bias Trick: vi (t ) + – VI iD =. | CIRCUITS AND ELECTRONICS Incremental Analysis Fall 2000 Lecture 7 1 Review Nonlinear Analysis Analytical method Graphical method Today Incremental analysis Reading Section Fall 2000 Lecture 7 2 Method 3 Incremental Analysis Motivation music over a light beam Can we pull this off vi t X vi t VD VD LED AMP LED AMP light light intensity I rc i Ir X IR light intensity IR V music si gnal in photoreceiver i t t LED Light Emitting expoDweep vI tiD t ww light ww iR t sound nonlinear linear problem will result in distortion Fall 2000 Lecture 7