| 摘要 |
PURPOSE:To improve the reliability of a magnetic disc device by changing the frequency characteristic of an LPF in correspondence to a track position of a magnetic head. CONSTITUTION:An N-channel junction gate FET15 connected in series with a capacitor 18 is provided in parallel with a capacitor 8 of a conventional circuit. This FET15 is connected to an output of a DA converter 16. A signal 17 representing the information of track position of the magnetic head is inputted to the converter 16, a voltage is produced in response to the track position and a resistance between the source and drain of the FET15 is changed accordingly. The LPF having a frequency characteristic suitable to each track position is realized by setting the output of the converter 16 exquisitely. |
