Patent ID: 6535017
Filing Date: 2003-03-18
Classification: H03K

Abstract:
A CMOS ECL input buffer having a buffer input and a buffer output, wherein the buffer input is arranged to receive an input signal from an ECL circuit, wherein the buffer output is arranged to provide an output signal to a CMOS circuit in response to the input signal from the ECL circuit, the CMOS ECL input buffer comprising:a CMOS differential amplifier having first and second inputs and an output; a CMOS input circuit coupled between the buffer input and the first input of the CMOS differential amplifier, wherein the CMOS input circuit is arranged to couple the input signal to the first input of the CMOS differential amplifier, and wherein the input signal has an ECL input voltage swing; a reference circuit coupled to provide a reference to the second input of the CMOS differential amplifier, wherein the reference is nominally set at substantially a midpoint of the ECL input voltage swing; and, a CMOS output circuit coupled between the output of the CMOS differential amplifier and the buffer output, wherein the CMOS output circuit is arranged to provide the output signal to the buffer output; wherein the output signal, in response to the CMOS differential amplifier, swings between a typical CMOS positive source voltage and ground as the input signal traverses the reference.