Stmicroelectronics S.r.l.

Francesco Piscitelli

Paolo Pulici

Dario Livornesi

Alessio Emanuele Vergani

Piero Malcovati

Enrico Mammei

Michele Bartolini

Mattia Fausto Moretti

Alessio Facen

Edoardo Bonizzoni

Roberto Faravelli

Mojtaba Mohammadi Abdevand

According to an embodiment, a circuit includes a core and low-frequency recovery circuits. The core circuit is configured to bias a resistive sensor used to measure a fly height of a hard disk drive. The core circuit is additionally configured to amplify a high-frequency component of a sensing signal of the resistive sensor, the sensing signal indicating the fly height. The low-frequency recovery circuit is configured to amplify the sensing signal's low-frequency component.

Circuit for biasing an external resistive sensor

According to an embodiment, a circuit includes a biasing and a low-frequency recovery circuit. The biasing circuit includes a voltage digital to analog converter (V-DAC), a differential difference amplifier coupled to the V-DAC, a common-mode feedback (CMFB) amplifier coupled to the differential difference amplifier, and a first pair of transistors arranged as a high-impedance structure and coupled to the differential difference amplifier and the CMFB amplifier. The low-frequency recovery circuit includes a current digital to analog converter (C-DAC), a second pair of transistors arranged as a high-impedance structure and coupled to the first pair of transistors, a pair of resistors having a resistance value equal to half a resistance of the resistive sensor, the pair of resistors arranged between the second pair of transistors and coupled to the C-DAC, and a gain circuit coupled to shared nodes between the second pair of transistors and the pair of resistors.

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Milan, Italy

Francesco Piscitelli