I simulated a simple noninverting amplifier using an operational amplifier in LTspice and i was wondering about the input impedance.
The input impedance of a noninverting amplifier should be the input impedance of the OPA itself plus the resistor to ground. The OPA I'm using (LT1014) should have an input resistance of 4 GOhm in common mode or 300 MOhm in differential mode according to it's datasheet.
But at a DC input of 0.1V LTspice shows a current of about 12nA through V3 which would suggest a resistance of just 8.3 MOhm (0.1V / 12*10^-9A).
Am I doing something wrong or what causes this huge discrepancy?