| 摘要 |
PURPOSE:To prevent an influence of a variation of a temperature by counting an active signal generated by the first and the second logical circuits by a serial data from the outside, and comparing it with a prescribed value, while an output of a fundamental clock of the same period as that of a think data is H and L. CONSTITUTION:A clock pulse generating circuit 1 generates a clock pulse phi1 and phi2 of an opposite phase to phi1, and inputs it to DFFs 2 and 3. At every period in which the pulse phi1 is an H level, when each clock pulse of a read data RD is inputted, a Q output of the DFF2 becomes H continuously, a Q' output becomes L, and a Q output of the DFF3 becomes L. While an H level of the DFF2 is inputted to an AND5 through an OR 4, the clock phi1 which is inputted is counted 7, inputted to a comparator 8, and when it reaches a prescribed value set in advance, a signal S is outputted. While the clock pulse phi2 is H, the circuit is operated in the same way as the DDF2 in cooperation with the DDF3. In this way, it is operated stably without being influenced by an ambient temperature. It is suitable for a think detector of a magnetic disk. |
