PURPOSE: To realize a phase control having the restoring property, by giving a control to the rise or fall phase of the timing regenerative wave through the variation of the threshold voltage and thus giving a continuous snd variable control to the rise or fall point of the timing regenerative wave.

CONSTITUTION: The input data is sent to the BPF2 via the terminal 1, and the timing frequency component is extracted. The output of the BPF2 is applied to the regenerative amplifier 3 for regeneration of the rectangular wave output. And the output of the amplifier 3 is sent to the integration circuit 4 for integration, and this output is applied to the regenerative amplifying circuit 5. On the other hand, the circuit 5 compares the input signal supplied from the circuit 4 with the threshold voltage sent from the threshold voltage input terminal 6, and then produces the rectangular wave for the period when the input signal voltage exceeds the threshold level. The threshold voltage is varied to give a control to the rise or fall phase of the timing regenerative wave in the circuit 5. As a result, a continuous and variable control is given to the rise or fall point of the timing regenerative wave, thus securing a phase control having the restoring property.