High speed magnetic recording

The maximum recording speed of a magnetic data storage device depends on the components in the recording channel, viz. electronics, interconnects, heads and media. The projected increase in device data rate (6-fold in 5 years) is higher than that for the electronics (silicon switching speed, 4-fold in 5 years). Driving the write head meets with “driving point impedance” limitations, linking the required MMF, the interconnect and head inductance, supply voltage and write current switching speed. Novel write drivers can break this link. Interconnect limitations and distributed read/write electronics are discussed. Write field waveforms and their dependence on the write current are presented. Various ways of improving the head switching time are treated. Finally, for the projected data rate increase to materialize, one has to solve all component limitations virtually simultaneously