Patent ID: 7365928

Claim:
A write driver circuit for driving current through a write head in a hard disk system, the driver being adapted to have an improved output dynamic range, the write driver comprising: an output node for connecting with an interconnect to the write head; means for receiving a supply voltage; a pair of current generators connected to the supply voltage receiving means and generating a pulsed current; a capacitance device with an input node and an output node, the input node being connected to the current generators, wherein the capacitance device output node is connected to the write driver circuit output node, whereby the pulsed current flows through the capacitance device to the write driver circuit output node; and an impedance matching circuit connected to the output node of the write driver circuit, the impedance matching circuit comprising a resistor having a resistance substantially equal to an odd character impedance of the interconnect to the write head, wherein the impedance matching circuit further comprises means for generating a voltage pulse to the resistor, the voltage pulse having an amplitude substantially equal to an output voltage at the output node of the write driver circuit, whereby the pulsed current is blocked from flowing through the resistor.