Pulse signal generator having delay stages and feedback path to control delay time

Claim 1

A pulse signal generator comprising a plurality of stages of delay gates connected in series for receiving an input pulse signal and generating a delayed output pulse signal, each stage consisting of a differential connection circuit and an emitter follower circuit, and having a signal delay time which is changed by varying a voltage that controls a value of the current flowing in a current sink of said differential connection circuit and that in a current sink of said emitter follower circuit, said pulse signal generator further comprising: a delay time signal generating circuit receiving said input and output pulse signals for forming a comparison pulse signal of a pulse duration corresponding to the delay time between said input and output pulse signals; a reference pulse signal generating circuit for forming, on the basis of a time constant of a capacitor and a resistor, a reference else signal of a pulse duration corresponding to a delay time of the input pulse signal derived from the passage thereof through a predetermined number of said delay gates; and a correction voltage generating circuit for forming a DC voltage corresponding to the difference between the pulse duration of said comparison pulse signal and that of said reference pulse signal; wherein the voltage for controlling the value of the current flowing in the current sink of each said differential connection circuit is supplied separately from the voltage for controlling the value of the current flowing in the current sink of each said emitter follower circuit, and the DC correction voltage outputted from said correction voltage generating circuit is supplied to the current sink of at least one of said emitter follower circuits to change the value of the current in the current sink, thereby controlling the delay time per stage of said delay gates.