During normal operation, the typical input bias current of the OPAx387 is 30 pA. The device exhibits low drift over the full temperature range of –40°C to +125°C. There are no antiparallel diodes between the input pins (+IN and –IN); therefore, the differential input maximum voltage is limited only by diodes connected to the supply voltage pins. However, use caution in cases where the input differential voltage exceeds the nominal operating input differential voltage. When inputs are separated, the switching offset-cancellation path internal to the amplifier exceeds normal operating conditions, and can potentially create long settling behavior upon return to normal operation. The equivalent input circuit of OPAx387 is shown in Figure 7-1.