INA333: cutt off frequency

Hi Jahangeer,

Thank you for your patience. Since your converter operates at 50 kHz, you generally want the cutoff frequency of the differential filter to be above this value to avoid attenuating your signal. Although it's difficult to provide a specific cutoff frequency without more information about your circuit, you could choose a differential cutoff frequency 2x your signal frequency (100 kHz). 

The following image is from page 6 of sbaa245a, which shows the input filter design steps in more detail. 

I would also recommend using the Analog Engineers Calculator, which has a calculator for determining the component values based on a target cutoff frequency.

Let me know if you have any other questions,

Alex Curtis

thank you for your information i am using opa2836 to sense the battery current do i need input filter for this opamp...

Hello Jahangeer,

I have moved this thread over to the high speed amplifiers team given that the OPA2836 is a high speed part.

In short, the need for input filtering depends on the performance requirements of your specific application. To answer your question, please provide more information about your application, such as a schematic, as well as the performance requirements for the current monitoring circuit. 

Best Regards,

Alex Curtis