| 摘要 |
PROBLEM TO BE SOLVED: To suppress a disturbance signal by extracting the disturbance signal from an inputted data signal, generating a switching signal on the basis of the disturbance signal and making the data signal pass through HPF in either H level mode or L level mode by the switching signal. SOLUTION: When a part on which a disturbance signal is superimposed, is inputted, a data signal exceeds a comparison voltage of a constant voltage source 17 by the disturbance signal and so, an output of a comparator 12 rises from at a first level to at a second level. The voltage level of the disturbance signal falls with the passage of time and the data signal becomes lower than the comparison voltage V1h1 of the voltage source 17, and the output of the comparator 12 falls from the second level to the first level. When the data signal becomes lower than the comparison voltage V1h1 , a NPN transistor TR12a becomes nonconductive and TR12b become conductive and the collector potential of TR12b is changed from a 1st to 2nd level transition, and a signal is outputted from the comparator 12. Thus, it is possible to suppress the disturbance superimposed on a reading data by a simple circuit constitution. |
