US 12,451,158 B2
Head gimbal assembly height determination with charge-to-voltage converter
Kin Wai Roy Chew, Singapore (SG)
Assigned to Avago Technologies International Sales Pte. Limited, Singapore (SG)
Filed by Avago Technologies International Sales Pte. Limited, Singapore (SG)
Filed on Oct. 31, 2023, as Appl. No. 18/499,119.
Prior Publication US 2025/0140287 A1, May 1, 2025
Int. Cl. G11B 5/48 (2006.01); G11B 5/60 (2006.01); G11B 21/12 (2006.01)
CPC G11B 5/4826 (2013.01) [G11B 5/486 (2013.01); G11B 5/6005 (2013.01); G11B 5/6017 (2013.01); G11B 21/12 (2013.01)] 20 Claims
OG exemplary drawing
 
1. 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.