An improved input buffer providing configurable single-ended and differential signaling capability, comprising an input signal comparator, a first pad connected to one input of the comparator. An internal reference voltage source may be connected to one terminal of a first selection switch. The second terminal of the first selection switch is connected to the second input of the comparator and one terminal of a second selection switch is connected to the second input of the comparator. Further, a second input pad is connected to the second terminal of the second selection switch. The invention also includes a mode selector that enables the first selection switch and disables the second selection switch for providing single-ended operation using the internal reference voltage source, or enables the second selection switch and disables the first selection switch for enabling differential operation or single-ended operation using an external voltage reference.