Part Number:INA333
Hi,
in my prototype I use a INA333 to get the difference between two (EMI) noisy signals.
The voltage variation is max 2V, with a max freq of 10 kHz. If any, I need very little gain.
Shielding is not possible, so filtering is the only option.
The INA333 should have good EMIRR capabilities, but to really eliminate as much as possible of the noise
(I am getting horrific Offset values) I want to use a filter before the INA.
However, I am want to ask you, what would be the better option:
a) Using a Unity Gain Buffer with an EMI-hardened Opamp like the OPA333 in front of the INA
(I know, this is a kind of redundance, but if I can eliminate noise in this way...)
or
b) Implementing a filter with a CM Choke followed by DM Filters, like in the figure
or
c) both
After the INA I go into an ADS8694, which has a front end inside. Following the datasheet, I suppose I do not need any filtering before it.
Many greetings from Germany!
Gustavo
