What are opamps?
Absolute Maximum Ratings (Differential Input Voltage)
Differential Input Voltage
The differential input voltage is the maximum voltage that can be supplied to the +Input (Non-inverting input) and -Input (Inverting input) pins without causing damage or degrading IC characteristics.
This voltage is suitable as a reference for both the inverting and non-inverting terminals, and refers to the voltage difference between both terminals. Polarity is not important.
However, the potential of each input terminal is assumed to be equal to or greater than the potential at the VEE pin.
The reason is that an ESD protection element is built into the IC, and if the potential at the input pin is lower than VEE, current will flow from the termnial through the ESD protection element, which can lead to characteristics deterioration and/or damage.
The protection element can be connected between VEE (GND) and the input pin, as shown in the left side of the below diagram, or between the input pins and VCC and VEE (GND), providing 2 pathways.
In the former case, since there is no path for current to flow at the VCC side, the differential voltage is determined based on the withstand voltage of the transistor (NPN, PNP) connected to the input terminal, regardles of the value of VCC.
In the latter case, because a protection element exists at the VCC side as well, since the input pin requires a potential less than VCC, the differential voltage is determined by VCC-VEE or VDD-VEE.
Some opamps utilize an NPN differential input stage, and in order to provide protection between the base and emitter, a clamping diode is inserted between the input terminals, or products with a differential input voltage of several volts are used.