Bandwidth calculation for inverting and no-inverting amplifier

jian wang87

Intellectual 370 points

please see below:

for non-inverting: BW = GBW / (1+R1/R2), right?

for inverting: also BW = GBW / (1+R1/R2), right?

thanks

over 4 years ago

0 Jacob Nogaj over 4 years ago

TI__Genius 12186 points

Hello,

You are correct in using the non-inverting gain to calculate bandwidth in both circuits (BW = GBW/ Non-inverting Gain).

For the schematics provided, the first circuit would posses an equation of BW = GBW/ (1+ R3/R2), and the second circuit, BW = GBW/ (1+ R5/R6).

If you need further resources for bandwidth calculation, this TIPL video offers lots of information on BW calculation and why inverting amplifiers use noise gain/non-inverting gain for BW calculation.

Let me know if you have any further questions,

Regards,

Jacob

0 Michael Steffes over 4 years ago in reply to Jacob Nogaj

Guru 48395 points

Hey Jian,

Your noise gain expressions are correct above, however the GBP analysis is a considerable oversimplification, came up again this AM on this thread you might find interesting,

https://e2e.ti.com/support/amplifiers/f/amplifiers-forum/989854/opa2354-gbw-and--3db-small-signal-bandwidth-difference

0 jian wang87 over 4 years ago in reply to Michael Steffes

Intellectual 370 points

thanks, it is very helpful.

0 jian wang87 over 4 years ago in reply to Jacob Nogaj

Intellectual 370 points

thanks very much for your quick response!

Amplifiers

Amplifiers forum

Bandwidth calculation for inverting and no-inverting amplifier