glias
Full Member level 2
Hello all,
I would want to understand why my input current of the minus input of my op amp vary with the resistor MCT sensor... ? For me input current of the op amp is composed of an offset current and a bias current : I-=Ibias-Ioffset/2, and this current should be a constant .. .?
How can I deduce the ac value of this current and thus the voltage error of my minus input ?
Is there any relation between the input current and input impedance of the op amp (Rdiff=5k ; Rcm=30M) to have a total input offset voltage ? or is this parameter is taken in account in the Vos voltage of the op amp ?
regards.
here is the schematic and plots (the blue one is the minus input current of the op amp)
I would want to understand why my input current of the minus input of my op amp vary with the resistor MCT sensor... ? For me input current of the op amp is composed of an offset current and a bias current : I-=Ibias-Ioffset/2, and this current should be a constant .. .?
How can I deduce the ac value of this current and thus the voltage error of my minus input ?
Is there any relation between the input current and input impedance of the op amp (Rdiff=5k ; Rcm=30M) to have a total input offset voltage ? or is this parameter is taken in account in the Vos voltage of the op amp ?
regards.
here is the schematic and plots (the blue one is the minus input current of the op amp)