BJT Differential Amplifier

anybody can help me with design and characterise a BJT transistor based differential amplifier with a gain of around 20.
please help me as soon possible.

attach the circuit or any suggsestion to me..thanks

This circuit show probably the most simple and functional differential amplifier stage there is.

If the bjt's in current mirrors doesn't match properly, you can always insert a resistor on each resistor emitter.

To get the gain you want, treat the circuit as a opamp and calculate a proper feedback.

Prototyp_V1.0 said:

This circuit show probably the most simple and functional differential amplifier stage there is.

If the bjt's in current mirrors doesn't match properly, you can always insert a resistor on each resistor emitter.

To get the gain you want, treat the circuit as a opamp and calculate a proper feedback.

Click to expand...

I think, TAC_T neeeds another circuitry that is even more simple: Replace the current mirror in the collector path by two resistors which can be used to set the gain.
Applying feedback for gain adjustment is not a good recommendation because of the medium range output resistance.

any idea of significance. materials, procedures, ect to build it?
Thank you

Then I can just throw out some links that should help:

wikipedia.org . . . Differential_amplifier
pdf file explaining

Or just do a seearch for "bjt differential amplifier".

Thank you for fast reply very

Private message going public:

Tac_T said:

Hey sorry to pvt msg you, but seem like you the only helping me out. Im a 1st years engineering student. My knowledge not very good with electric stuffs. Its there a different ways to design and characterise a BJT transistor based differential amplifier with a gain of around 20? too the one u gave me?

Thank you very much for all your help

Click to expand...

Hi. We take discussion public.

I didn't realize you're first year student so you probably haven't been through op-amp chapters yet. But you DO have done some calculations on differential amplifiers.
I gave you some of the links. There is a LOT of reading on the web. You will find it.

And trust me - when exam time is beyond next corner, you'll be happy that you learned this yourself. If I just calculated those values for you, it would help you nada.