# BJT analog circuit design

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1. Jun 16, 2015

### GGGboat

1. The problem statement, all variables and given/known data
hello, i need to design analog circuit that has a transfer curve as seen in the following image using resistors, capacitors,voltage, and BJT (with beta value of 100).
the parameters are:
A=75
f1= 21Hz
f2=21 KHz
M1=40
M2=-20

the circuit also need to have input resistance of Rin= 60 kilo-ohm and output resistance of 51 kilo-ohm.

2. Relevant equations
I posted this yesterday and it was deleted so first of all, let me apologize if i gave the impression that i was trying to get you guys to do my homework for me. i most certainly wasn't (sorry I'm just pretty clueless at this point).

does my 3-stages solution make sense(see part 3:solution attempt)? is it the right approach?
how do I know which of the following modules should I use for each stage?

3. The attempt at a solution

i think the circuit should have 3 stages, each connected with a capacitor, where the first stage is for achieving the required input resistance, the second for the required gain, and the third is for the required output resistance.

(the first and last stages might also add some gain but it will be considered in the second stage)

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• ###### transfer_curve.PNG
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2. Jun 16, 2015

### GGGboat

f1 and f2 are the frequencies where the dotted lines are.

3. Jun 16, 2015

### rude man

Well, which module(s) has/have the necessary gain?
Pick one or more and give us your first effort at a design.

4. Jun 16, 2015

### LvW

M1=40
M2=-20

According to your diagram. one can get the impression that M1=20 and M2=-40 is required ?
Question: How do you intend - in principle(!) - to realize the corner frequencies?