The differential output buffer, the difference input buffer, the semiconductor integrated circuit, and the circuit substrate

摘要

PPROBLEM TO BE SOLVED: To solve the problem that a differential input buffer, etc., malfunctions in receiving differential signals, if a cross-point potential deviates greatly from a reference voltage, and a detector circuit itself causes malfunction for a high operating frequency, even though a control trigger signal is checked in HH or LL detection. PSOLUTION: The differential output buffer 10 comprises a positive side output buffer 11P and a negative side output buffer 11N. Each output buffer has an output stage, a variable delay gate 114 and a fixed delay gate 115, to control the gates of transistors 112, 113 with outputs of the gates 114, 115. A differential input buffer block 20 comprises a differential input buffer 22 having inputs of a positive side signal and a reference voltage 31, a differential input buffer 23 having inputs of a negative side signal and the reference voltage, and a phase comparator 28 for making a control clock and data from the comparison result, to increase the delay in the variable delay gate 114 and set a cross point voltage to the reference voltage. PCOPYRIGHT: (C)2004,JPO