Seagate Technology Incorporated

Chee Wee Cheng

Myint Ngwe

Beng Theam Ko

Quan Li

Liu Li

Andy Chou

Zhen Yu Sun

A method for detecting a contact event between a transducer and a recording medium is disclosed. The method includes positioning a transducer with respect to a recording medium, where the transducer includes a writer, a reader, a heater, and a thermally responsive sensor. The method further includes applying power to the heater to establish a fly height of the transducer; supplying a bias current through the thermally responsive sensor to generate a bias signal; measuring a root mean square (RMS) voltage Vof the thermally responsive sensor based on the bias signal; determining a threshold voltage V; and detecting a contact event between the transducer and the medium based on Vbeing greater than V.

In situ sensor based contact detection

The disclosure is related to pulse width modulating a power signal to a heat resistive element of a transducer. The power signal may be a power output signal of preamplifier. The power signal may be provided to a heat resistive element in a transducer that is operable to read data from or write data to a data storage medium. The pulse width modulated power signal can allow for controlling the heating of the heat resistive element based on a thermal time constant of the heat resistive element and based on adjustable components of the pulse width modulated power signal.

Controlling a heat resistive element with a pulse modulated signal

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Singapore, Singapore

Chee Wee Cheng