DIFFERENTIAL AMPLIFIER, SIGNAL DETECTION CIRCUIT, DETECTION CIRCUIT FOR SERIAL DATA SIGNAL AND SERIAL DATA RECOVERY CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a differential amplifier, a signal detector, a detector for serial data and a serial data recovery device especially suitable for detecting the existence of signals of serial data at high speed. SOLUTION: A differential circuit composed of first an second transistor M1 and M1 for inputting the signals of serial data of differential signals and a differential circuit composed of third and fourth transistors M3 and M4 for inputting offset signals are provided and a comparator is provided for comparing the level of the node of the drains of the first and third transistors M1 and M3 with the level of the node of the drains of the second and fourth transistors M2 and M4. While no serial data signal is applied, an output level from the comparator is fixed and when the serial data signal is applied, an output for changing the level corresponding to input data can be provided. Such a signal detecting circuit enables high speed operation and can detect the existence of signals of high speed serial data in CMOS configuration.