摘要 |
A noise eliminating circuit eliminates thermal asperity noise in a reproduction signal generated by a magnetic read head in a disk drive. The noise eliminating circuit includes a differential amplifier that receives the reproduction signal and a feedback signal and generates an amplified signal. A detection circuit connected to the differential amplifier detects noise in the amplified signal and generates a control signal. The control signal is activated when the noise is detected. A feedback circuit connected to the differential amplifier and the detection circuit cuts off the amplified signal with a first cutoff frequency when the control signal is not active and cuts off the amplified signal with a second cutoff frequency when the control signal is active.
|