Write-to-servo common mode DC offset recovery accelerator, after AE-channel DC blocking capacitor
Original Publication Date: 2000-Jul-01
Included in the Prior Art Database: 2003-Jun-20
External low impedance network by pull-up(down) resistors, is prepared at input of read/write circuit channel module IC to accelerate common mode DC offset recovery after write operation. In read signal pass between AE amplifier and channel, usually DC blocking capacitors are used to adjust DC level for channel input stage. New level is given by charge discharge current from channel internal pull-up resister or internal current source. If AE amplifier has DC offset between write and read mode, and in case that read operation starts just after write (read servo between write operation), DC level cannot be adjusted fully and that results in servo failure such as ID error or bad positioning by wrong wedge amplitude.