Maker Pro
Maker Pro

Differential Op amp CMRR

pump

Nov 4, 2011
24
Joined
Nov 4, 2011
Messages
24
Hi,

I need to design a differential op-amp circuit that has a minimum CMRR of 50dB and a max input voltage of 1mV

If anyone could point me in the right direction it would be great

Cheers
 

OLIVE2222

Oct 2, 2011
690
Joined
Oct 2, 2011
Messages
690
Hi Pump,

Welcome to this forum. Differential op amp can be build on various way by using 1 to 3 op amp. The CMRR is frequeny depending.
If your desgin is theoretical you can be in a perfect world an choice the 1 opamp design with very tight components specifications. Practical design would probably be a 2 or 3 op amp one.

Just google a little bit and you will find many informations, mainly on analog devices and Texas Instruments sites. TI even offer a free simulation package.
Olivier
 

pump

Nov 4, 2011
24
Joined
Nov 4, 2011
Messages
24
Hi Thank you for your responce.

It is just theroy and will keep looking

Thank you
 

foTONICS

Sep 30, 2011
332
Joined
Sep 30, 2011
Messages
332
i believe shorting the inputs and using an external trimpot until your output has a CMRR of 50dB is a nice way of doing it
 
Top