| 摘要 |
<p>A read channel circuit includes a high frequency filter (14) and a pair of differentiators (16, 18), one of which is a high resolution differentiator (16) and the other of which is a low resolution differentiator (18) intentionally adjusted to perform its differentiation function imperfectly. Comparators (32) serve as zero crossing detectors for the high and low resolution signals. The comparator for the low resolution path provides the data input to a flip-flop (34). The comparator for the high resolution path has its output processed by an exclusive OR gate (38) and a delay circuit (44) before being applied to the clock input (46) of the flip-flop. The high-resolution and low-resolution paths are combined in the flip-flop (34), whose digital output faithfully reproduces the binary information received by the read head by deriving timing from the high-resolution path and by effectively discriminating against artifacts in the read head's signal which would result in spurious transitions in the read channel's output were it not for the imperfect differentiation provided in the low-resolution path.</p> |
