模拟电路设计第6章.ppt

Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 1 Chapter 6 Frequency Response of Amplifiers Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 2 Simple Pole vi vo vo / vi 1 / sCR 1 / sC vo / vi 1sR C 1 vo vi ( f ) 1 1 j 2 f R C vo vi ( f ) 1 1 j f fp , fp 1 / 2 RC Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 3 Miller Effect Z 1 Z( 1 A v ) Z 2 Z(1 A 1 v ) Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 4 Miller Capacitive Multiplication C 1 C F ( 1 A v ) C 2 C F ( 1 A 1 v ) C F Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 5 Applicability of Millers Theorem Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 6 Poles and Nodes Interacting Poles Non-Interacting Poles Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 7 Common Gate f pX 1 2 C GS C SB R S | 1 g m g mb f pY 12 C GD C DB R D Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 8 Common Source f p , in 12 R S C GS ( 1 g m R D ) C GD f p , o u t 12 C GD C DB R D Neglecting input/output interaction, Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 9 Common Source (cont.) f p , in 12 R S C GS ( 1 g m R D ) C GD R D ( C GD C DB ) A s s u m e D s p 1 1 s p 2 1 s 2 p 1 p 2 s p 1 1 , p 2 p 1 vo vi ( sC GD g m ) R D s 2 R S R D ( C GS C GD C GS C SB C GD C DB ) s R S ( 1 g m R D ) C GD R S C GS R D ( C GD C DB ) 1 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 10 Common Source (cont.) f p , o u t R S ( 1 g m R D ) C GD R S C GS R D ( C GD C DB )2 R S R D ( C GS C GD C GS C DB C GD C DB ) f p , o u t 12 R D ( C GD C DB ) , f o r la r g e C GS f p , out g m R S R D C GD 2 R S R D ( C GS C GD C GS C DB C GD C DB ) gm 2 ( C GS C DB ) , f o r l a r g e C GD Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 11 Common Source (cont.) Right half plane zero, from the numerator of vo/vi sC GD g m . . . f z g m 2 C GD vo vi ( sC GD g m ) R D s 2 R S R D ( C GS C GD C GS C SB C GD C DB ) s R S ( 1 g m R D ) C GD R S C GS R D ( C GD C DB ) 1 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 12 Source Follower (Common Drain) vo vi g m sC GS s 2 R S ( C GS C L C GS C GD C GD C L ) s g m R S C GD C GD C GS g m f p 1 g m 2 g m R S C GD C L C GS , a s s u m in g f p 2 f p 1 1 2 R S C GD C L C GS g m Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 13 Source Follower Input Impedance A t l o w f r e q u e n c i e s , g mb | sC L | Z in 1 sC GS 1 g m / g mb 1 / g mb C in C GS g mb /( g m g mb ) C GD ( s a m e as M ille r ) N e g le c t i n g C GD , Z in 1 sC GS 1 g m sC GS 1 g mb sC L Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 14 Source Follower (cont.) A t h i g h f r e q u e n c ie s , g mb | sC L | Z in 1 sC GS 1 sC L g m s 2 C GS C L At a particular frequency, input impedance includes CGD in parallel with series combination of CGS and CL and a negative resistance equal to -gm/(CGSCL2). Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 15 Source Follower Output Impedance Z OUT V X / I X sR S C GS 1 gm sC GS 1 / g m , at lo w f r e q u e n c ie s R S , at h ig h f r e q u e n c ie s Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 16 Source Follower Output Impedance (cont.) R 2 1 / g m R 1 R S 1 / g m L C GS g m R S 1 / g m Output impedance inductance dependent on source impedance, RS! Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 17 Source Follower Ringing Output ringing due to tuned circuit formed with CL and inductive component of output impedance. Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 18 Cascode Stage Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 19 Cascode Stage (cont.) f pA 1 2 R S C GS 1 C GD 1 1 g m 1 g m 2 g mb 2 f pX g m 2 g mb 22 C GD 1 C DB 1 C SB 2 C GS 2 f pY 12 R D C DB 2 C L C GD 2 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 20 Differential Pair Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 21 Differential Pair (cont.) Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Slides prepared by Travis N. Blalock, University of Virginia. Frequency Response Ch. 6 # 22 Differential Pair (cont.) f p 1 12 ( r oN | roP ) C L f p 2 g mP2 C E f Z 2 f p 2 2 g mP2 C E