BALANCED EMBEDDED CONTACT SENSOR WITH LOW NOISE ARCHITECTURE

摘要

Approaches for a hard-disk drive (HDD) having a balanced resistive temperature detector (RTD). A HDD includes a head slider comprising a single RTD. A read/write IC comprises a balance resistor having the same resistance as the single RTD when the head slider is not in physical contact with the disk. The same amount of current flows through the single RTD and the balance resistor except when the head slider is in physical contact with the disk. Detecting a voltage change across the single RTD enables physical contact between the head slider and the disk to be accurately detected using a circuit with low noise. Alternately, the head slider may include two RTDs connected in sequence, and the balance resistor may possess the same resistance as the two RTDs. The two RTDs may vary inversely with environmental changes to avoid the need to recalibrate the balance resistor after any environmental change.