C = 5uF output cap, can not give a answer because we do not know the load to the right of the cap.off frequency of each capacitor
Avmid=Vo2/Vi , Avs =Vo2/Vs
Only at frequencies where the bypassing is effective. The problem asks for the "cutoff frequency" of each capacitor, so that means to consider the effect of CE.Since Re is bypasses, Av = Rc/R'e
What network analysis techniques have you learned? Superposition, branch, nodal, mesh?Hello,
I am really confused, please can someone help me with this task. Thanks in advance
That is an interesting little amplifier.
That is an interesting little amplifier.
They are giving the transistor Betas so i would think you have to do a full analysis to find the cutoff frequencies caused by each capacitor. For the output capacitor you will have to consider the equivalent resistance infinite.
I dont think there are any shortcuts because for example the input impedance of the bottom transistor works with the input cap as well as the bias resistors. So you have some work to do here.
Do you have to calculate this or can you use a simulator?
That is an interesting little amplifier.
They are giving the transistor Betas so i would think you have to do a full analysis to find the cutoff frequencies caused by each capacitor. For the output capacitor you will have to consider the equivalent resistance infinite.
I dont think there are any shortcuts because for example the input impedance of the bottom transistor works with the input cap as well as the bias resistors. So you have some work to do here.
Do you have to calculate this or can you use a simulator?
Dear Sir, first of all I have to draw the re model and I really dont know how to draw it. Can you help with it firstly?That is an interesting little amplifier.
They are giving the transistor Betas so i would think you have to do a full analysis to find the cutoff frequencies caused by each capacitor. For the output capacitor you will have to consider the equivalent resistance infinite.
I dont think there are any shortcuts because for example the input impedance of the bottom transistor works with the input cap as well as the bias resistors. So you have some work to do here.
Do you have to calculate this or can you use a simulator?
Dear Sir, thanks for your interest. I must use the re model, because of our professor’s requirementAre you really required to use the "re" model?
For my opinion, it is the worst model and can create confusion...as an example: In post '4' it is written as R´e.
This is confusing (and wrong) because re is a differential quantity and must be written in small letters.
More than that - and strictly spoken - it is NOT a resistance...
Why not using models with a voltage-controlled current source (transconductance gm) or a current-controlled current source?
These models have more physical relevance than the re model.
re is 26mV/IE, so I think first we have to find Ie. Will be waiting for your helpThe re model is fine you just have to know full well how to use it and calculate the value of re itself.
Furthermore, the re model does not preclude the use of a current controlled current source for the transistor in fact it works very well with it.
Also in fact, once you calculate re you can calculate the gain quite easily and it will MATCH the simulation exactly.
So first, do you know how to calculate the value of re?
Since the β of Q1 and Q2 is a rather high 200, for a first approximation you could ignore the base currents and calculate the current in the 3 bias resistors, and thence the voltage at the bases of Q1 and Q2. Then the voltage at the emitter of Q1 will follow, which gives the emitter current. Can you do all this? Show your work.re is 26mV/IE, so I think first we have to find Ie. Will be waiting for your help
OK - I know what you mean...and I suppose you are refering to the second re-model as shown in the following linkThe re model is fine you just have to know full well how to use it and calculate the value of re itself.
Furthermore, the re model does not preclude the use of a current controlled current source for the transistor in fact it works very well with it.
Also in fact, once you calculate re you can calculate the gain quite easily and it will MATCH the simulation exactly.
So first, do you know how to calculate the value of re?
Oh well the way i draw it and the way you might find it on the web are two different things. The way i draw it accounts for the Vbe voltage drop while most of the models i see on the web only have re.Dear Sir, first of all I have to draw the re model and I really dont know how to draw it. Can you help with it firstly?
by Luke James
by Jake Hertz
by Luke James