Multi-stage amplifier design

Thread Starter

Musab

Joined Sep 20, 2008
25
Hi,

I am asked to design a multistage amplifier using BJT transistors. The gain of the circuit should be 100dB and covering a frequency from 100Hz to 10MHz.

I was thinking of using a common emitter stage followed by an emitter follower, but I realized that the gain required is too big. will it be possible to achieve that gain using this configuration ?

Also, I know how to calculate the capacitor values needed in a single stage circuit, but how is that done in a multistage circuit ?


Thanks,
 

hobbyist

Joined Aug 10, 2008
889
Hi,

I am asked to design a multistage amplifier using BJT transistors. The gain of the circuit should be 100dB and covering a frequency from 100Hz to 10MHz.

I was thinking of using a common emitter stage followed by an emitter follower, but I realized that the gain required is too big. will it be possible to achieve that gain using this configuration ?


Thanks,
No, because an emitter follower has loss of voltage gain.
 

t_n_k

Joined Mar 6, 2009
5,455
Hi,

I am asked to design a multistage amplifier using BJT transistors. The gain of the circuit should be 100dB and covering a frequency from 100Hz to 10MHz.

I was thinking of using a common emitter stage followed by an emitter follower, but I realized that the gain required is too big. will it be possible to achieve that gain using this configuration ?

Also, I know how to calculate the capacitor values needed in a single stage circuit, but how is that done in a multistage circuit ?


Thanks,
A reasonably wideband amplifier with a voltage gain of 100,000 [100dB] like this is not a trivial design exercise. Is this just a paper design or something you have to build and demonstrate? You need to show some effort in this since it's homework.

At least do some searching on the web yourself. There are sure to be examples - with designs both by professionals and hobbyists.
 
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