Seagate Technology Incorporated

Lan Xia

Quek Leong Choo

Xiong Liu

Myint Ngwe

Lihong Zhang

Quan Li

Beng Wee Quak

Song Wee Teo

Fong Kheon Chong

Swee Chuan Samuel Gan

Ben Niu

Teng Hou Sebastian Chua

Apparatus and method for reducing the effects of thermal asperities on a rotatable data recording surface. A data transducer writes user data to a first set of tracks at a first fly height above the recording surface. A compensation circuit detects a thermal asperity (TA) on the recording surface, and establishes a guard band as a second set of tracks that are co-radial with the TA. The second set of tracks are deallocated and removed from service. The compensation circuit further defines a reserve band as a third set of tracks immediately adjacent the guard band, and selects an increased, second fly height that allows the data transducer to write data to the reserve band without contacting the TA. The second set of tracks may have a greater track pitch than the first set of tracks to compensate for the greater fly height.

Adaptive configuration of thermal asperity guard bands

The disclosed technology provides techniques for mitigating write-to-write bit error rate fluctuations that decrease accuracy of write precompensation (WPC) tuning. According to one implementation, such write-to-write bit error rate fluctuations are mitigated if a predetermined pattern is written at a particular radial offset from a target data track prior to testing a WPC register in association with the target data track. Selection of the particular radial offset can be performed according to an iterative offset track clean-up disclosed herein.

Noise mitigation for write precompensation tuning

A method of categorizing magnitudes of thermal asperities in a read-back signal of a data storage system includes receiving the read-back signal from a location containing a thermal asperity. A peak magnitude signal is generated from the read-back signal. A threshold signal is generated using a variable threshold generator. The peak magnitude signal is compared to the threshold signal and a magnitude of the thermal asperity is categorized as a function of the comparison.

Thermal asperity multi-threshold algorithm using the read/write channel

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Singapore, Singapore

Lan Xia