This preview shows pages 1–5. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Lectures 29 and 30 More opamp circuits Some causal intuition Opamp doesnt respond instantly, but has infinite gain if: dV out /dt=k(V +V ) If (V +V )>0, V out b eventually For the circuit shown, So, if Vin steps from 0V b 1V Vout slopes downward But this decreases V1 Vout slope decreases Vout settles to constant as: 1 1 1 R R R V R V V F out F in + + = R F R 1 V 1 V in V out + F F in out F F in F out R R V V R R R V R R R V V = + + 1 1 1 1 1 1 R R R V V F F in + Vin V1 Vout Some causal intuition If hook it up in positive feedback For the circuit shown, So, if Vin steps from 0V b 1V Vout slopes UPWARD This increases V1 Vout slope increases Vout, V1 rise until the hit the maximum or minimum output voltage. 1 1 1 R R R V R V V F out F in + + = R F R 1 V 1 V in V out + 1 1 R R R V V F F in + Vin V1 Vout Useful example: transimpedance amplifier What is Vout?...
View
Full
Document
 Spring '05
 KELLEY/SEYLER

Click to edit the document details