a differential output buffer formed on a monolithic semiconductor substrate characterized by a bias generator coupled to a voltage source and a output stage coupled to the bias generator . the bias generator develops a bias output having a voltage level less than that of the voltage source . the output stage is responsive to a pair of complementary cmos logic level inputs and uses the bias output of the bias generator to develop a pair of corresponding , low voltage swing outputs . in one embodiment the bias generator and the output stage operate in an open - loop and produce output signals which swing approximately two volts and in another embodiment the bias generator and the output stage operate in a closed - loop configuration and produce output signals which swing approximately one volt .