Frequently Asked Question
Is digital potentiometer a real replacement for mechanical potentiometer or are there restrictions regarding voltage potentials?
Strictly speaking, digital potentiometer is not an exact replacement for mechanical potentiometer. The larger one of VA and VB must be smaller than or equal to VDD, and the smaller one of VA and VB must be greater than or equal to VSS, or GND if the part does not have a VSS pin. For example, if the desired VA and VB are +2V and -2V, then VDD must be >= +2V and VSS must be <= -2V. In any case, voltages across terminals W-A, W-B, or A-B of all digital potentiometers (except AD7376, AD5260/2, AD5280/82, AD5290, and AD5263) should be limited to |5V|, the polarity constraint.