{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

EE 230 Lecture 15 Spring 2010

# EE 230 Lecture 15 Spring 2010 - EE 230 Lecture 15 Basic...

This preview shows pages 1–8. Sign up to view the full content.

EE 230 Lecture 15 Basic Applications of Operational Amplifiers Differential Amplifiers Impedance Converters Nonideal Op Amp Characteristics (if time permits)

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

View Full Document
Applications of integrators to filter design () 0 BP 22 0 0 Is Ts s+Is+ I α = Design Strategy ( ) 1 Tj ω 1 2 1 The 2 nd order Bandpass Filter 0 I s 0 I s + 1. Pick C (use some practical or convenient value) 2. Solve expression to obtain R 3. Solve expression to obtain α and thus R Q 0 1 I= RC P0 ω = I P 1 ω = RC BW= RC RC Assume BW and ω P are specified Review from Last Time
Another 2 nd -order Bandpass Filter () 3 2 2 12 3 1 s RC Ts = - 21 s+s + R //R RC ⎛⎞ ⎜⎟ ⎝⎠ 1 2 BW = P 3 1 ω = R R //R C ( ) BP Tj ω K K 2 1 3 R K= 2R Design Strategy 1. Pick C to some practical or convenient value 2. Solve expression to obtain R 1 3. Solve expression to obtain α and thus R 3 4. Solve expression to obtain R 2 1 2 BW = Assume BW, ω P , and K are specified 1 3 R K= 2R P 3 1 ω = R R //R C Review from Last Time

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

View Full Document
STAR 2 nd -order Bandpass Filter () ( ) 1 3 2 2 12 3 2 3 1 sH RC H -1 Ts = - 21 s+s + R C R //R H-1 R //R R C ⎛⎞ ⎜⎟ ⎝⎠ Works fine ! Reduces to previous bandpass filter at H gets large Note that the “H” amplifier has feedback to positive terminal Implementation: ??? If op amp ideal, OUT IN V = H V Will discuss why this happens later! Review from Last Time
Differential Amplifiers Many applications exist for difference (differential) amplifiers Differential amplifiers are widely used Strain gage is one application that demonstrates some challenges http://www.omega.com/prodinfo/straingages.html Wheatstone Bridge http://en.wikipedia.org/wiki/Strain_gauge Metal foil strain gages V OUT is very small compared to V B and V D Assume V A is ground

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

View Full Document
Differential Amplifiers Ideal differential amplifier ( ) OUT IN1 IN2 V= A V - V R OUT =0 R IN = All Ideally the output is not dependent upon the size of V IN1 or V IN2 but only upon their difference This creates a challenge when designing differential amplifiers
Differential Amplifiers Differential amplifier application SG OUT EXC D SG SG R R V = V A - R+R R+R ⎛⎞ ⎜⎟ ⎝⎠ SG OUT EXC D SG RR = V A R+R Let SG R= R + Δ R OUT EXC D EXC D V = VA 2R+ R 2R ΔΔ Δ ± If Δ

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 26

EE 230 Lecture 15 Spring 2010 - EE 230 Lecture 15 Basic...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online