A CMOS input buffer supporting multiple I/O standards and having a pair of NMOS and PMOS differential receivers, each having a first input connected to an input pad and a second input connected to a reference voltage, a first multiplexer connected to the control terminal of the current sink of the NMOS differential receiver and having one input connected to the positive supply terminal, and a second multiplexer connected to the control terminal of the current source of the PMOS differential receiver and having one input connected to the negative supply terminal or ground. The buffer further includes an inverter connected to a combined output of the PMOS and NMOS differential receivers and having an output connected to the second input of the first and second multiplexer, and a configuration storage bit for selecting the desired inputs of the first and second multiplexer, thereby supporting high speed standards as well as general purpose standards while reducing static power dissipation.