[Design] 1mV 100 Gain Amplifier with Bandwidth 20Mhz

[TuAtAu]

As title, I want to amplify a 1mV with an op-amp as non-inverting amplifier. Gain is 100. But it's just went wrong.. and the amplified voltage is always -48mV...

and I want BW more than 20Mhz in 100 gain.. what should i do T.T

using Op-amp AD811
https://www.analog.com/static/imported-files/data_sheets/AD811.pdf

 

[neddie]

First thing is to post the cct , difficult to help when we've got no idea what you have done.

---------- Post added at 13:04 ---------- Previous post was at 11:19 ----------

First off I don't think the GBW of that opamp is up to the job. You won't get a gain of 100 at 20MHz.
If the output is always -48mV --- Are you running dual supply?

 

[muthukumar_ece2004]

According to your requirements, it should be 2GHe of GBW. I suggest you to use THS4511 type of op-amp.

 

[neddie]

Or use more gain stages if you have more than 1 AD811 lying around.
Getting a gain of 100 at 20MHz in one stage will dictate being careful
with your layout. You don't want to turn your amplifier into an oscillator.
Remember - amplifiers WILL , oscillators WON't :0)