Browse Prior Art Database

Data Detection Circuit

IP.com Disclosure Number: IPCOM000085561D
Original Publication Date: 1976-Apr-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 60K

Publishing Venue

IBM

Related People

Au, S: AUTHOR [+2]

Abstract

This is a circuit for detecting data read from a magnetic recording medium. The waveform A shows information written on the recording medium, wherein each binary 1 represents a change from one level of flux polarity to the opposite level and a binary 0 is represented by no change. The block diagram shows the circuitry for reading back the data.

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Data Detection Circuit

This is a circuit for detecting data read from a magnetic recording medium. The waveform A shows information written on the recording medium, wherein each binary 1 represents a change from one level of flux polarity to the opposite level and a binary 0 is represented by no change. The block diagram shows the circuitry for reading back the data.

A transducer senses the changes in flux recorded on the medium and produces a signal shown by waveform B at the data-in line. This signal is integrated and amplified at block 10. The integrated signal is equalized at amplifier 12 to produce a three-level data signal, which varies to a DC reference level to a positive level and return and from the DC reference level to a negative level and return, the variations corresponding to recorded data bits. (See waveform C.)

In this equalized signal each binary 1 is characterized by a zero crossing. This three-level signal is full-wave rectified and squared up by the data full-wave rectifier 14. The squared signal is shown in waveform D. To reduce the effect of spurious unwanted noise, clip levels are utilized shown by the dotted lines in waveform C so that only signals rising above this clip level are squared up by the full-wave rectifier 14.

A data strobe 16 responds to the three-level data signal to produce strobe pulses at zero crossings, for the purpose of locking the data in with a clocking circuit. (See waveform E.) The clocking circuit is comprised of...