LM2904: LM2904 | GBW Query

Subrahmanyam V

Intellectual 480 points

Part Number: LM2904

Hi,

I read a GBW of 700 kHz in the LM2904.

So, If I implement a gain of 10 using the op-amp, I have a bandwidth of 70 kHz.

What is my BW when I implement a PI controller using the same? Zero?

Please help me clear this doubt.

Thanks,

Subrahmanyam

over 5 years ago

0 Ron Michallick over 5 years ago

TI__Guru**** 167546 points

Hello Subrahmanyam,

700 kHz is typical performance. so close to 70 kHz small signal bandwidth. Please explain term, "PI controller". Is this PID without the D? Or is it a raspberry PI controller?

0 Subrahmanyam V over 5 years ago in reply to Ron Michallick

Intellectual 480 points

My apologies for the ambiguous word, Ronald.

I meant a P-I (Proportional - Integral) controller.

0 kai klaas69 over 5 years ago

Guru 140200 points

Hi Subrahmanyam,

yes, you have a bandwith of 70kHz then. But to make the OPAmp work properly you need a gain reserve of at least 20dB. So you can only use a bandwidth of <7kHz.

Kai

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LM2904: LM2904 | GBW Query