| 摘要 |
PROBLEM TO BE SOLVED: To regulate variations in the head output characteristics within an AGC input dynamic range of the read channel in a head IC adjusting the amplitude level of the signals read by the head. SOLUTION: An AGC amplifier (10) is formed on the head IC (103) connected to the read channel (102) and the feedback response speed of the AGC circuit (14) of the head IC (103) is set sufficiently slower than the feedback response speed of the AGC circuit (107) of the read channel (102). Further, a peak hold circuit (23) and an amplitude limiter circuit (25) are formed in the head IC (103) to adjust the gain by the holding value in the peak hold circuit. Thus, the initial gain can be adjusted quickly and stably without being affected by small amplitude signals on the medium. COPYRIGHT: (C)2008,JPO&INPIT
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