iF = (0-VZ)/R1 iZ = iS + iF = (Vs-VZ)/Rs -VZ/R1 0.1IZ ≥ Vs (0.1IZ +VZ/R1)Rs + VZ ≥ (2008S1 exam question) Answer: Inverting node: (V- -Vs1)/R + (V- -Vs2)/R = (Vout-V-)/(R/2) 2V- -Vs1 -Vs2 = 2 (Vout-V-) Non-inverting node: V+ = 0 Negative feedback V+ = V- -Vs1 -Vs2 = 2 Vout Vout = -(Vs1 +Vs2)/2 = -(18+12)/2 = -15 (mV)
iF = (0-VZ)/R1 iZ = iS + iF = (Vs-VZ)/Rs -VZ/R1 ≥ 0.1IZ Vs ≥ (0.1IZ +VZ/R1)Rs + VZ (2008S1 exam question) Answer: Inverting node: (V- -Vs1)/R + (V- -Vs2)/R = (Vout-V-)/(R/2) 2V- -Vs1 -Vs2 = 2 (Vout-V-) Non-inverting node: V+ = 0 Negative feedback V+ = V- -Vs1 -Vs2 = 2 Vout Vout = -(Vs1 +Vs2)/2 = -(18+12)/2 = -15 (mV)
Part%20II_Tutorials.docx