# Finding the resistor and capacitor values of an amplifier with some requirements

#### army07

Joined May 22, 2016
5
Hi guys,
i'm new around here and i really need your helps.
So i have a tiny project and it's about designing an amplifier.

The design requirements are;

Rin= 60k
Rout=50 ohm
Voltage gain= +100
Bandwidth= Between 50Hz - 10kHz or more.

I was wondering if u guys can help me. So i searched on the internet and looked some kinda book pdfs. For high input resistance, i think i have to build a common emitter amplifier circuit. And then, for low output resistance i need common collector ( emitter follower ) circuit. So my full circuit must be 2 stage amplifier CE-CC. Could you please help me finding the resistor and capasitor values for this design?

#### army07

Joined May 22, 2016
5
I think my circuit should look like this.

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#### shteii01

Joined Feb 19, 2010
4,644
I think my circuit should look like this.
Does that circuit comes with an explanation or is it some random circuit from the internetz?

#### army07

Joined May 22, 2016
5
it's a random circuit. i learned from some pdfs that i should use CE circuit for high Rin and CC circuit for low Rout. I thought that if i combine this 2 circuits, maybe i can get what is expected. But i couldn't find any calculations about it.

#### shteii01

Joined Feb 19, 2010
4,644
it's a random circuit. i learned from some pdfs that i should use CE circuit for high Rin and CC circuit for low Rout. I thought that if i combine this 2 circuits, maybe i can get what is expected. But i couldn't find any calculations about it.
I just don't see how you can do this problem with other people guiding you. I am not an educator, so to do this problem I would have to sit down and do it myself all the way, which basically useless because then you are not solving it, I am solving it for you. This problem builds on many simpler smaller tasks that are taught earlier. The fact that you don't have the knowledge of those previous smaller simpler tasks means that you will not be able to do the work on this problem yourself. Which brings up a question: Who or what are you? If you are a student and this is your course material, then WTF were you doing earlier? If you are not a student, then you need to take this problem to the Project subforum because this is not Homework.

#### MrAl

Joined Jun 17, 2014
11,717
Hi guys,
i'm new around here and i really need your helps.
So i have a tiny project and it's about designing an amplifier.

The design requirements are;

Rin= 60k
Rout=50 ohm
Voltage gain= +100
Bandwidth= Between 50Hz - 10kHz or more.

I was wondering if u guys can help me. So i searched on the internet and looked some kinda book pdfs. For high input resistance, i think i have to build a common emitter amplifier circuit. And then, for low output resistance i need common collector ( emitter follower ) circuit. So my full circuit must be 2 stage amplifier CE-CC. Could you please help me finding the resistor and capasitor values for this design?

Hi,

What is this amplifier going to be used for?

You may be on the right track, but amplifiers often have feedback to help improve the signal distortion and other stuff. Can you use op amps too or you have to use transistors only?

#### shteii01

Joined Feb 19, 2010
4,644
Hi,

What is this amplifier going to be used for?

You may be on the right track, but amplifiers often have feedback to help improve the signal distortion and other stuff. Can you use op amps too or you have to use transistors only?
My WAG. Judging by frequency, speech level audio.