PURPOSE: To obtain a minute delay time which can be adjusted with high accuracy, by giving an input signal to a base of transistors (TRs) of a diferential amplifier and feeding back a voltage difference between both collector outputs to another base after being split at a variable resistor.

CONSTITUTION: An input signal IN is applied to a base of a pair TRs Q1, Q2 constituting a differential amplifier. A collector output of the TRs Q1, Q2 is obtained via buffer TRs Q3, Q5 and a fixed resistor R3 and an MOSTRQ4 are connected in series between emitters of the TRs Q3, Q5. A potential B1 at a connecting point between the fixed resistor R3 and a TRQ4 is fed back to the base of the TRQ1 and a resistance value of the TRQ4 is controlled with a control voltage CONT. Thus, the amount of feedback is changed with the control voltage CONT to change the amount of delay.