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AD8253 input current

Question asked by D.T. on Oct 9, 2017
Latest reply on Oct 15, 2017 by D.T.


I use ADIsimPE to simulate AD8253. From the datasheet, the input current should be <50nA. However, from simulation I see ~8uA current goes into the amplifier. I'm wondering is it realistic? How come a CMOS opmap has such large input current?


For a very basic test, vinp=vinm, I intentionally use R2=100K, and R3=10K. The output is 7.4V due to the input current flow through unequal resistor.