Op Amp Bypass

[tom_pay]

Hi

What does the bypass pin on an Op Amp do?

I understand that it is for decoupling. But decoupling what?

Is it basically like the capacitor that is put on the power lines of a PIC, just on a different pin to do something internally?

I'm sorry about my simple question, but I'm really confused.

Tom

 

[#12]

Umm...yes...considering that I am guessing exactly which op-amp you are talking about.

 

[EN0]

So tom_pay (catch the word, fellas?), will you pay us to research this concept for you? C'mon now, it doesn't take much to google this! Start here.

I love that website! Don't you?

 

[crutschow]

I don't know of any op amps with a "bypass" pin. What op amp are you referring to?

 

[Jaguarjoe]

Are you talking about the capacitor such as the one between pins 1 & 8 on this IC?

https://www.electro-tech-online.com/custompdfs/2010/12/LM101A.pdf

Or are you talking about the capacitor such as the one from pin 7 to gnd on this IC?

https://www.electro-tech-online.com/custompdfs/2010/12/LM386.pdf

 

[audioguru]

Yesterday he wrongly called an LM380 an opamp but instead it is a power amp with a "bypass" pin. Its datasheet describes that a capacitor on its bypass pin reduces power supply noise on its output. Then he asked why he can't filter the power supply noise by using a huge and expensive supply bypass capacitor instead of a little inexpensive one on the "bypass" pin.

 

[tom_pay]

Thanks for your help. I understand it better now.

Tom

PS I like the Google thing!!!