Method and apparatus for decreasing a transition time of a read head from a write mode to a read mode

摘要

A device for switching from the write mode to the read mode includes a read head connected between a first and a second input terminal of the differential amplifier, the second input terminal being connected to a constant voltage through a capacitor and to the amplifier output through the resistor. The apparatus includes a circuit for generating a voltage ramp, after a write operation; a circuit for discharging an initial current in the read head proportionally to the voltage ramp between the beginning of the ramp and a first threshold voltage of the ramp; a switch for shorting the resistor to a low value, at least between the first threshold voltage and a second ramp threshold voltage; and a detector for detecting the second threshold voltage and for providing, in the vicinity of the threshold, a progressive control of the switch.