Unterschiede

Hier werden die Unterschiede zwischen zwei Versionen angezeigt.

Link zu dieser Vergleichsansicht

Beide Seiten der vorigen Revision Vorhergehende Überarbeitung
Nächste Überarbeitung
Vorhergehende Überarbeitung
circuit_design:uebung_2.1.4 [2023/03/09 15:25] mexleadmincircuit_design:uebung_2.1.4 [2023/03/27 14:20] (aktuell) mexleadmin
Zeile 4: Zeile 4:
 <imgcaption imageIdealizedDiode | Idealized Diode> <imgcaption imageIdealizedDiode | Idealized Diode>
 </imgcaption> </imgcaption>
-{{drawio>ImageIdealizedDiode}}+{{drawio>ImageIdealizedDiode.svg}}
 </WRAP> </WRAP>
  
-The differential resistance $r_D$ of a diode was already described in the chapter. This is necessary if a diode is to be simulated via a simplified diode model (voltage source + resistor + ideal diode, if applicable). In <imgref imageIdealizedDiode>, see the differential conductance $g_D={{1}\over{r_D}}$ as the local slope at the desired operating point. +The differential resistance $r_\rm D$ of a diode was already described in the chapter. This is necessary if a diode is to be simulated via a simplified diode model (voltage source + resistor + ideal diode, if applicable). In <imgref imageIdealizedDiode>, see the differential conductance $g_{\rm D}={{1}\over{r_\rm D}}$ as the local slope at the desired operating point. 
-Calculate the differential resistance $r_D$ at forward current $I_D=15 mA$ for room temperature ($T=293~K$) and $m=1$ from Shockley's equation: ${I_F I_S(T)\cdot (e^{\frac{U_F}{m\cdot U_T}}-1)}$ with $U_T = \frac{k_B \cdot T}{e}$. +Calculate the differential resistance $r_\rm D$ at forward current $I_\rm D=15 ~\rm mA$ for room temperature ($T=293~\rm K$) and $m=1$ from Shockley's equation: ${I_{\rm F} I_{\rm S}(T)\cdot ({\rm e}^{\frac{U_\rm F}{m\cdot U_\rm T}}-1)}$ with $U_{\rm T} = \frac{k_{\rm B} \cdot T}{q}$ with $q=1~\rm e$. 
-To do this, first calculate the general formula for the differential resistance $r_D$.+To do this, firstcalculate the general formula for the differential resistance $r_\rm D$.
  
 Steps: Steps:
-  - First, simplify Shockley's equation for $U_F \gg U_T+  - First, simplify Shockley's equation for $U_{\rm F} \gg U_\rm T
-  - Find a formula for $\frac {d I_F}{d U_F}$. +  - Find a formula for $\frac {{\rm d} I_{\rm F}}{{\rm d} U_\rm F}$. 
-  - Again, replace part of the result with $I_F$ and rotate the fraction to calculate the differential resistance by $r_D = \frac {d U_F}{d I_F}$. \\ As a result, you should now have $r_D = \frac {d U_F}{d I_F} = \frac {m \cdot U_T}{I_F} $  +  - Again, replace part of the result with $I_\rm F$ and rotate the fraction to calculate the differential resistance by $r_{\rm D} = \frac {{\rm d} U_\rm F}{{\rm d} I_\rm F}$. \\ As a result, you should now have $r_{\rm D} = \frac {{\rm d} U_\rm F}{{\rm d} I_\rm F} = \frac {m \cdot U_\rm T}{I_\rm F} $  
-  - Calculate $r_D$. +  - Calculate $r_\rm D$. 
  
 </WRAP></WRAP></panel> </WRAP></WRAP></panel>