Cutoff Freq of Inverting Op Amp

Thread Starter


Joined Jan 15, 2012
Hi guys,

The question I need help with is
"Determine the maximum gain possible that meets the high-frequency roll-off specification of fH = 20 kHz."

As you can see from my schematic & bode plot, I designed the roll-on to be at 100Hz and it rolls off at 815kHz.

How do I mathematically find the bandwidth or the cutoff frequency? I understand that to find the roll-on you simply do 1/(2piR2C1). I assume that once I find out how to find cutoff freq, I can design the roll-off at 20kHz and find the gain.

Thank you,



Joined Mar 14, 2008
Do you understand the "gain-bandwidth product" specification of op amp amplifiers? It's determined by the internal frequency response of the op amp, not the external components. If you understand that (Google if needed) then you can answer your own question.