Unterschiede

Hier werden die Unterschiede zwischen zwei Versionen angezeigt.

Link zu dieser Vergleichsansicht

Beide Seiten der vorigen Revision Vorhergehende Überarbeitung
Nächste Überarbeitung		 Vorhergehende Überarbeitung
electrical_engineering_and_electronics_1:block21 [2025/12/14 22:16] – mexleadminelectrical_engineering_and_electronics_1:block21 [2026/01/10 10:05] (aktuell) – mexleadmin
Zeile 1: Zeile 1:
 ====== Block 21 — Op-Amp Basics ====== ====== Block 21 — Op-Amp Basics ======
  
-===== Learning objectives =====+===== 21.0 Intro ===== 
 + 
 +==== 21.0.1 Learning objectives ====
 <callout> <callout>
 After this 90-minute block, you can After this 90-minute block, you can
Zeile 14: Zeile 16:
 </callout> </callout>
  
-===== Preparation at Home =====+==== 21.0.2 Preparation at Home ====
  
 Well, again  Well, again 
Zeile 23: Zeile 25:
   * ...   * ...
  
-===== 90-minute plan =====+==== 21.0.3 90-minute plan ====
   - Warm-up (10 min):   - Warm-up (10 min):
     - Hook: audio amplifier clipping example (undistorted vs overdriven waveform/spectrum) → why “ideal amplification” is not automatic.     - Hook: audio amplifier clipping example (undistorted vs overdriven waveform/spectrum) → why “ideal amplification” is not automatic.
Zeile 51: Zeile 53:
     - Common pitfalls checklist (below).     - Common pitfalls checklist (below).
  
-===== Conceptual overview =====+==== 21.0.4 Conceptual overview ====
 <callout icon="fa fa-lightbulb-o" color="blue"> <callout icon="fa fa-lightbulb-o" color="blue">
   - Think of an op-amp as a **differential voltage sensor + powerful output stage**:   - Think of an op-amp as a **differential voltage sensor + powerful output stage**:
Zeile 71: Zeile 73:
 </callout> </callout>
  
-===== Core content =====+===== 21.1 Core content =====
  
 <WRAP>  <WRAP> 
Zeile 77: Zeile 79:
 <WRAP> <WRAP>
  
-==== Introductory example ====+==== 21.1.1 Introductory example ====
  
 Acoustic amplifiers, such as those found in mobile phones, laptops, or hi-fi systems, often exhibit an unpleasant characteristic when heavily amplified: the previously undistorted signal is no longer passed on as usual, but [[https://en.wikipedia.org/wiki/Total_harmonic_distortion#Definitions_and_examples|clatters]]. It is distorted in such a way that it no longer sounds pleasant. Acoustic amplifiers, such as those found in mobile phones, laptops, or hi-fi systems, often exhibit an unpleasant characteristic when heavily amplified: the previously undistorted signal is no longer passed on as usual, but [[https://en.wikipedia.org/wiki/Total_harmonic_distortion#Definitions_and_examples|clatters]]. It is distorted in such a way that it no longer sounds pleasant.
Zeile 111: Zeile 113:
  
  
-==== Circuit symbols and basic circuitry ====+==== 21.1.2 Circuit symbols and basic circuitry ====
  
 This chapter deals with operational amplifiers. One application for these are the measurement of voltages, currents, and resistances. \\ These values must be determined very precisely in some applications, for example for accurate temperature measurement. In this case, amplification of the measurement signals is useful and necessary. This chapter deals with operational amplifiers. One application for these are the measurement of voltages, currents, and resistances. \\ These values must be determined very precisely in some applications, for example for accurate temperature measurement. In this case, amplification of the measurement signals is useful and necessary.
Zeile 153: Zeile 155:
  
 ~~PAGEBREAK~~ ~~CLEARFIX~~ ~~PAGEBREAK~~ ~~CLEARFIX~~
-==== Basic Equation / Golden Rules ====+==== 21.1.3 Basic Equation / Golden Rules ====
  
 The operational amplifier is a voltage amplifier. It simply measures on one side the voltage (like a voltmeter) and provides an amplified voltage on its output (like a voltage source). \\  The operational amplifier is a voltage amplifier. It simply measures on one side the voltage (like a voltmeter) and provides an amplified voltage on its output (like a voltage source). \\ 
Zeile 238: Zeile 240:
  
 ~~PAGEBREAK~~ ~~CLEARFIX~~ ~~PAGEBREAK~~ ~~CLEARFIX~~
-==== Feedback ====+==== 21.1.4 Feedback ====
  
 One of the fundamental principles of control engineering, digital technology, and electronics is **feedback**. \\ One of the fundamental principles of control engineering, digital technology, and electronics is **feedback**. \\
Zeile 310: Zeile 312:
  
  
-===== Common pitfalls =====+===== 21.3 Common pitfalls =====
   * **Mixing up the inputs:** confusing the inverting input $U_{\rm m}$ (minus) with the non-inverting input $U_{\rm p}$ (plus). A wrong sign flips the whole behavior.   * **Mixing up the inputs:** confusing the inverting input $U_{\rm m}$ (minus) with the non-inverting input $U_{\rm p}$ (plus). A wrong sign flips the whole behavior.
   * **Wrong differential voltage:** forgetting that $U_{\rm D}$ = $U_{\rm p}$ - $U_{\rm m}$.   * **Wrong differential voltage:** forgetting that $U_{\rm D}$ = $U_{\rm p}$ - $U_{\rm m}$.
Zeile 325: Zeile 327:
  
  
-===== Learning Questions =====+===== 21.4 Learning Questions =====
  
   * Explain the difference between the unipolar and bipolar power supply of an opamp.   * Explain the difference between the unipolar and bipolar power supply of an opamp.
Zeile 333: Zeile 335:
   * What is the basic equation of the opamp?   * What is the basic equation of the opamp?
  
-===== Exercises =====+===== 21.5 Exercises =====
  
 <panel type="info" title="Exercise 1.3.2 Calculations for negative feedback"> <panel type="info" title="Exercise 1.3.2 Calculations for negative feedback">
Zeile 358: Zeile 360:
 </WRAP></WRAP></panel> </WRAP></WRAP></panel>
  
-<panel type="info" title="Exercise 21.1 — Op-amp basics: symbols and signs">+<panel type="info" title="Exercise 21.1 Op-amp basics: symbols and signs">
   * Given an operational amplifier symbol, label the following quantities:   * Given an operational amplifier symbol, label the following quantities:
       - non-inverting input voltage $U_{\rm p}$,       - non-inverting input voltage $U_{\rm p}$,
Zeile 376: Zeile 378:
 </panel> </panel>
  
-<panel type="info" title="Exercise 21.2 — Differential vs single-ended thinking">+<panel type="info" title="Exercise 21.2 Differential vs single-ended thinking">
 An op-amp has $A_{\rm D}=150{'}000$ and is powered from $\pm 12\,\rm V$. An op-amp has $A_{\rm D}=150{'}000$ and is powered from $\pm 12\,\rm V$.
   - Compute $U_{\rm O}$ for $U_{\rm p}=1.002\,\rm V$ and $U_{\rm m}=1.000\,\rm V$ (ideal equation).   - Compute $U_{\rm O}$ for $U_{\rm p}=1.002\,\rm V$ and $U_{\rm m}=1.000\,\rm V$ (ideal equation).
Zeile 383: Zeile 385:
 </panel> </panel>
  
-<panel type="info" title="Exercise 21.3 — Unipolar supply and output biasing">+<panel type="info" title="Exercise 21.3 Unipolar supply and output biasing">
 An op-amp operates from a unipolar supply $0\,\rm V$ to $9\,\rm V$. An op-amp operates from a unipolar supply $0\,\rm V$ to $9\,\rm V$.
   - What output voltage corresponds to “zero differential input” in a typical unipolar configuration?   - What output voltage corresponds to “zero differential input” in a typical unipolar configuration?
Zeile 390: Zeile 392:
 </panel> </panel>
  
-<panel type="info" title="Exercise 21.4 — Unipolar supply and virtual ground intuition">+<panel type="info" title="Exercise 21.4 Unipolar supply and virtual ground intuition">
 An op-amp uses a unipolar supply $0\,\rm V \dots 10\,\rm V$. \\ An op-amp uses a unipolar supply $0\,\rm V \dots 10\,\rm V$. \\
 If you want to amplify a small sinus signal centered around $0\,\rm V$, why is it a problem to connect it directly to an input? If you want to amplify a small sinus signal centered around $0\,\rm V$, why is it a problem to connect it directly to an input?
 </panel> </panel>
  
-<panel type="info" title="Exercise 21.5 — Classify feedback (fast diagnosis)">+<panel type="info" title="Exercise 21.5 Classify feedback (fast diagnosis)">
   * For each statement, mark **true/false** and correct the false ones:   * For each statement, mark **true/false** and correct the false ones:
       -  Feeding back a fraction of the output to the inverting input always creates negative feedback.       -  Feeding back a fraction of the output to the inverting input always creates negative feedback.
Zeile 406: Zeile 408:
 </panel> </panel>
  
-<panel type="info" title="Exercise 21.6 — Saturation and clipping reasoning">+<panel type="info" title="Exercise 21.6 Saturation and clipping reasoning">
 An op-amp is powered from $\pm 5\,\rm V$ (bipolar). The output swing is limited to about $\pm 4\,\rm V$. An op-amp is powered from $\pm 5\,\rm V$ (bipolar). The output swing is limited to about $\pm 4\,\rm V$.
   - If $U_{\rm D}=+50\,\mu\rm V$ and $A_{\rm D}=200{,}000$, compute the ideal $U_{\rm O}$. Is saturation expected?   - If $U_{\rm D}=+50\,\mu\rm V$ and $A_{\rm D}=200{,}000$, compute the ideal $U_{\rm O}$. Is saturation expected?
Zeile 413: Zeile 415:
 </panel> </panel>
  
-<panel type="info" title="Exercise 21.7 — Input bias currents (qualitative + estimate)">+<panel type="info" title="Exercise 21.7 Input bias currents (qualitative + estimate)">
 A sensor with source resistance $R_{\rm S}=1\,\rm M\Omega$ drives the non-inverting input. \\ A sensor with source resistance $R_{\rm S}=1\,\rm M\Omega$ drives the non-inverting input. \\
 The real op-amp dows not only show an internal resistance, but also a small current source on the input pins. \\ The real op-amp dows not only show an internal resistance, but also a small current source on the input pins. \\
Zeile 421: Zeile 423:
 </panel> </panel>
  
-<panel type="info" title="Exercise 21.8 — Output current limit and load selection">+<panel type="info" title="Exercise 21.8 Output current limit and load selection">
 A real op-amp can supply at most $I_{\rm O,max}=20\,\rm mA$. \\  A real op-amp can supply at most $I_{\rm O,max}=20\,\rm mA$. \\ 
 It is intended to drive a load resistor $R_{\rm L}$ from an output voltage of $U_{\rm O}=3\,\rm V$. It is intended to drive a load resistor $R_{\rm L}$ from an output voltage of $U_{\rm O}=3\,\rm V$.