[SOLVED] Amplifier without op-amp

[TuAtAu]

Hi, Another have any idea to build an amplifier without Op-Amp?
I want it able to amplify the 10mV to any voltage until 3.3V. Any idea how to do it without OpAmp?

(Challeges: 10mV can't even bias a transistor..)

 

[FvM]

I presume, as for any amplifier. there will be a supply voltage. It's surely able to bias a transistor.

The amplifier needs more specification. To start with an essential point, AC or DC signal?

 

[TuAtAu]

Hi FvM

Its DC signal.

I just want the idea. because when take off of op amp. My mind suddenly blanked..

I try to use BJT amplifier, but the Vt or Vbe need 0.7V to bias right? Does Vcc able to help? I don't mind to have Vcc bias supply.

 

[FvM]

For a DC signal, you should consider differential transistor pairs as input stage and possibly multiple amplifier stages to achieve the intended gain.

 

[crutschow]

For stable DC amplification you need a differential input transistor pair as FvM stated. Such a differential pair is biased in the active region so the 0.7V part of the bias circuit, not the DC amplification of the pair. Basically that is the input stage of an op amp.