Abstract: A circuit for determining head gimbal assembly (HGA) height is provided. The circuit includes a first switch configured to be controlled by a first clock signal, an amplifier, and a first capacitor coupled to the first switch, wherein the first capacitor is formed by at least part of a head gimbal assembly and a storage media. The circuit further includes a second capacitor coupled to an input of the amplifier, and an output of the amplifier, wherein the second capacitor is configured to store a charge from the first capacitor over one or more cycles of the first clock signal. The amplifier is configured to generate an output voltage based, at least in part, on a change in the capacitance of the first capacitor over the one or more cycles of the first clock signal.

Abstract: A method of operating a controller for a power converter having a plurality of switches couplable to respective electrical devices is disclosed, in which the controller includes a switch activating unit, a frequency varying unit, a comparator and a selector. The method comprises comparing respective electrical parameters of the electrical devices with respective reference electrical parameters by the comparator to obtain associated results; and based on the results, selecting by the selector either no switches or at least one switch to be activated to enable at least two electrical devices to be electrically connected. The activation is performed on receipt of a signal pulse, and if no switches are selected, the signal pulse is skipped by the switch activating unit to reduce power consumption of the controller, and based on the results, a frequency of the signal pulse is varied by the frequency varying unit to further reduce power consumption of the controller. A controller is also disclosed.

Abstract: A method of operating a controller (200) for a power converter having a plurality of switches couplable to respective electrical devices (106, 108, 110) is disclosed, in which the controller includes a switch activating unit (210), a frequency varying unit (202), a comparator (206) and a selector (208). The method comprises comparing respective electrical parameters of the electrical devices with respective reference electrical parameters by the comparator to obtain associated results; and based on the results, selecting by the selector either no switches or at least one switch to be activated to enable at least two electrical devices to be electrically connected. The activation is performed on receipt of a signal pulse, and if no switches are selected, the signal pulse is skipped by the switch activating unit to reduce power consumption of the controller, and based on the results, a frequency of the signal pulse is varied by the frequency varying unit to further reduce power consumption of the controller.