LT1679
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The LT1678/LT1679 are dual/quad rail-to-rail op amps offering both low noise and precision: 3.9nV/vHz wideband noise, 1/f corner frequency of 4Hz and 90nV...
Datasheet
LT1679 on Analog.com
Hi wbadry,
What is your source impedance in this configuration where you replaced MCP6004 with LT1679 and got higher noise reading?
If your input impedance is "high", you'd want to choose a device which has low current noise density. LT1679 input current noise density is higher than MCP6004. It is also a 20MHz part vs. 1MHz for MCP6004. So, it could be that you need to reduce your closed loop bandwidth to reduce excess noise beyond your freq range of interest.
Here are some suggestions:
Quad: LTC6082, LTC6088, or AD8648.
Single: AD8615, or AD8605.
Regards,
Hooman