US Patent 7760460 Head integrated circuit and storage apparatus including the same

A head integrated circuit for driving a head. The head includes at least a head unit and a heating element for adjusting the spacing between the head and a storage medium. The head integrated circuit includes at least a read amplifier for amplifying the read signal from the head unit and a heater drive circuit for driving the heating element. The heater drive circuit includes a measuring circuit configured to measure the level of power supplied to the heating element, an error calculating circuit configured to calculate an error between a predetermined power level and the measured power level, a pulse width modulation circuit configured to modulate the error into a pulse width, and a switch configured to operate in response to a pulse from the pulse width modulation circuit and supply power to the heating element.