Head gimbal assembly height determination with charge-to-voltage converter
AssigneeAvago Technologies International Sales Pte. Limited
InventorKin Wai Roy Chew
Life of this patent
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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.
Claims20
An apparatus comprising:
- a first circuit comprising:
- a first switch configured to be controlled by a first clock signal, the first switch comprising a first terminal and a second terminal;
- an amplifier comprising an inverting input, noninverting input, and an output, wherein the inverting input is coupled to the second terminal;
- a first capacitor coupled to the first terminal of the first switch, wherein the first capacitor is formed between a head gimbal assembly and media;
- and
- a second capacitor comprising third terminal and fourth terminal, the third terminal coupled to the inverting input of the amplifier, and the fourth terminal coupled to the 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,
- wherein 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.
A system comprising:
- a head gimbal assembly;
- a storage media, wherein capacitance is formed between at least part of the head gimbal assembly and the storage media;
- and
- a circuit configured to determine a height of the head gimbal assembly relative to the storage media, the circuit comprising:
- a first subcircuit comprising:
- a first switch configured to be controlled by a first clock signal, the first switch comprising a first terminal and a second terminal;
- an amplifier comprising an inverting input, noninverting input, and an output, wherein the inverting input is coupled to the second terminal;
- a first capacitor coupled to the first terminal of the first switch, wherein the first capacitor is formed by at least part of the head gimbal assembly and the storage media;
- and
- a second capacitor comprising third terminal and fourth terminal, the third terminal coupled to the inverting input of the amplifier, and the fourth terminal coupled to the 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,
- wherein 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.
A circuit comprising:
- a first switch configured to be controlled by a first clock signal, the first switch comprising a first terminal and a second terminal;
- an amplifier comprising an inverting input, noninverting input, and an output, wherein the inverting input is coupled to the second terminal;
- a first capacitor coupled to the first terminal of the first switch, wherein the first capacitor is formed by at least part of a head gimbal assembly and a storage media;
- and
- a second capacitor comprising third terminal and fourth terminal, the third terminal coupled to the inverting input of the amplifier, and the fourth terminal coupled to the 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,
- wherein 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.
Dependencies are inferred from the claim text.