PURPOSE: To prevent a transmitting circuit from malfunctioning, by adding two flip-flops, an inverter, and a 3-input AND gate.

CONSTITUTION: An input signal Si is applied to a flip-flop 1, which is operated by a clock signal CL; and a flip-flop 2 is also operated similarly and their outputs Q1 and Q2 are applied to a latch circut 3 to be latched by a latch signal S1, transmitting them to output termnals C01 and C02. In this case, the output of a flip-flop 4 is inverted by an inverter 6 and applied to the 3-input AND gate 7 together with the outpt Q4 of the flip-flop 4 and the latch signal S1; and the latch signal 3 is put in operation by the output of the AND gate 7 to hold the last data even when the clock signal CL contains chattering or noise components, preventing the malfunction.