Part Number:THS4631
Tool/software: WEBENCH® Design Tools
Dear All,
I have designed a 1MHz Trans Impedance Amplifier around a THS4631 op-amp. My issue is that measured noise of the system is as much as 10 times higher than the simulated noise. Also, my hand calculations differs from WEBENCH predictions, in particular the current noise referred to the output. I have used the approach detailed in Jerald Graeme book (Photodiode Amplifiers – Op amp solutions) as well as the step by step noise calculation detailed in chapters 10 and 11 of Art Kay’s excellent book (Operational Amplifier Noise).
I have attached the document detailing my design as well as the WEBENCH report below.
(Please visit the site to view this file)
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Can anyone help explain the discrepancies between my calculations and WEBENCH values please? In particular, is my total current noise calculation incorrect?
Thank you for your help.
Herve.