I use INA826 to convert an audio signal diff to single. Vs = 3.3V and Vicm = 1.65V and Vref = 1.65V G = 1
in datasheet, it is said the Vicm max in V+ - 1V.
In the datasheet, figure 9, the Vicm seems to be over limited when Vs = 3V (Vicm max is 1.5V)
==> I understand my design should not work.
I test my case with TINA ans it works.
Am I wrong or Tina is wrong ?
Hello Sylvain,
Sorry for the delay.
Concerning the linear operating region of the INA826, please refer to this page:
There is a link to a common-mode vs. output swing tool on that site. I used that tool to create the figure below:
Notice that the linear operating region of the output is from ~0.95V to ~2.35V assuming VS=3V, Vref=1.65V, G=1V/V, and Vicm=1.65V.
Please note that the TINA SPICE models do not model Vcm vs. Vout behavior, which is why your simulation may work but it does not work in the real world. Finally, please note that Figures 9 and 10 in the data sheet should have an upper Vcm range closer to 2V instead of 1.5V, as you noted that Vicm max is (V+)-1V.
I hope this helps!
