 #1
PhysicsTruth
 116
 18
 Homework Statement
 Analyze qualitatively, the output impedance and the open loop gain of a IC 741 OpAmp from its internal circuit.
 Relevant Equations

##V_{out} = A_{o} ( V_{in1}  V_{in2})##
##A_{o}## is the open loop voltage gain.
Here is the internal circuit of the 741 OpAmp 
Looking at the output stage, the output impedance seems to be the series combination of ##25 \Omega## and ##50 \Omega##, that is ##75 \Omega##. Is this a qualitative explanation enough to justify the output impedance, or am I wrong somewhere and need to take into account some other impedances as well.
Coming to the openloop gain, the output PushPull amplifier has no voltage gain, only it's achieved at the Darlington pair and the initial input stage emitter followers. How do I go on to claim qualitatively that the open loop gain is significantly high, and nearing infinity?
Looking at the output stage, the output impedance seems to be the series combination of ##25 \Omega## and ##50 \Omega##, that is ##75 \Omega##. Is this a qualitative explanation enough to justify the output impedance, or am I wrong somewhere and need to take into account some other impedances as well.
Coming to the openloop gain, the output PushPull amplifier has no voltage gain, only it's achieved at the Darlington pair and the initial input stage emitter followers. How do I go on to claim qualitatively that the open loop gain is significantly high, and nearing infinity?