Circuit for biasing an external resistive sensor

A hard disk drive assembly, comprising:

• a hard disk drive;
• a resistive sensor configured to measure a fly height of the hard disk drive;
• a first circuit configured to amplify a high-frequency component of a sensing signal of the resistive sensor, the sensing signal indicating the fly height of the hard disk drive;
• and
• a second circuit configured to amplify a low-frequency component of the sensing signal.

A hard disk drive assembly, comprising:

• a hard disk drive;
• a resistive sensor configured to measure a fly height of the hard disk drive;
• a first circuit configured to amplify a high-frequency component of a sensing signal of the resistive sensor, the sensing signal indicating the fly height of the hard disk drive, the first circuit comprising:
• a pair of amplifiers,
• a voltage-biasing digital-to-analog converter,
• a first pair of transistors having control terminals coupled to the voltage-biasing digital-to-analog converter,
• a second pair of transistors having control terminals coupled to a respective one of the pair of amplifiers, the second pair of transistors coupled to the resistive sensor.