Gating with OpAmp

[radio]

Hello

How do I achieve gating with an OpAmp?

Is lowering voltage reference in case of an inverting opamp

the only possibility?

Greetings JMErnzer

[Paul Perry (Frostwave)]

radio, what do you mean by 'gating'?
If you mean, switching the amp on and off, that certainly is not the way to do it!
Two simple ways are:
1. an operational transconductance amplifier like a LM13700 wiht the bias switched, or
2. a fet (or analog switch chip) arrranged to form a voltage divider & short out the signal when off.

Cutting the power to an op amp, or swinging the bias hard over, doesn't always result in what you might expect (think bleed through in the firat case, and possible latch-up or destruction in the second).

[radio]

Paul Perry

My vote goes to 1. , but can I use CA3080 as well?

Here is the starting point of my search ,nearer to you than to me

http://g2d.co.nz/products/productdetail.php?ID=4

I though they'd only used OpAmps like tl072 for that one.

The idea with the OTA did not even come to my mind :oops:

Thanks for leading me to the correct track!

Greetings JMErnzer