440_hmk4_soln

440_hmk4_soln - ECE 440 Electronics II Solutions to...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
ECE 440 – Electronics II Solutions to Homework #4 1. a. A f = A 1 + β A = 50 1 + .5(50) = 1.92 b. dA f A f = 1 1 + A dA A = 1 1 + 25 (15%) = 0.58% c. dA f A f = A 1 + A d = (.5)(50) 1 + (.5)(50) (15%) = 14.4% 2. A f = A 1 + A = 2 × 10 5 1 + 1 + 2 × 10 5 1 + = 2 × 10 5 1 + 2 × 10 5 + = 2 × 10 5 1 + 2 × 10 5 1 + 10 1 + 2 × 10 5 ( ) a. A of = 2 × 10 5 1 + 2 × 10 5 = 2 × 10 5 1 + (0.5)2 × 10 5 = 2 b. BW = 10(2 β x 10 5 ) = 1MHz c. G-BW = 2 MHz 3. DC Analysis, open all of the capacitors: For Q1, find the Thevenin equivalent for the input circuit and write KVL around the input loop, resulting in: 47 K 47 K + 150 K (25) = (150 K ||47 K ) I C 1 + 0.7 + 4.8 KI C 1 I C 1 = 0.964 mA g m 1 = 0.0367 r π 1 = 1362 Ω Similarly for Q2: 33 K 47 K + 33 K (25) = (33 K K ) I C 1 + 0.7 + 4.7 KI C 1 I C 1 = 1.89 mA g m 1 = 0.073 r 1 = 689 Ω The feedback network is: = v f v o = 100 4800 = 0.0208 100 4700 + v o - + v f -
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
redrawing the “A” amplifier with the feedback loading the circuit: In order to correctly use the feedback formulas we need to replace the circuit to the left of Q1 with its Thevenin equivalent: where V TH = 150 K ||47 K 150 K K + 5 K V i = 0.8774 V i R 1 = r π 1 + β + 1 ( ) 100 ||4.7 K ( ) = 6258 Ω A = v o v TH = 10 K ||4.7 K ||4.8 K ( ) r 1 + + 1 ( ) 100 ||4.7
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/24/2009 for the course ECE 440 taught by Professor Alizahid during the Fall '07 term at CSU Northridge.

Page1 / 4

440_hmk4_soln - ECE 440 Electronics II Solutions to...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online