US 12,073,860 B2
Circuit for biasing an external resistive sensor
Dario Livornesi, Milan (IT); Alessio Emanuele Vergani, Milan (IT); Paolo Pulici, Legnano (IT); Francesco Piscitelli, Milan (IT); Enrico Mammei, Vittuone (IT); Mojtaba Mohammadi Abdevand, Pavia (IT); Piero Malcovati, Pavia (IT); and Edoardo Bonizzoni, Pavia (IT)
Assigned to STMicroelectronics S.r.l., Agrate Brianza (IT)
Filed by STMicroelectronics S.r.l., Agrate Brianza (IT)
Filed on Mar. 28, 2023, as Appl. No. 18/191,639.
Claims priority of provisional application 63/346,717, filed on May 27, 2022.
Prior Publication US 2023/0386514 A1, Nov. 30, 2023
Int. Cl. G11B 5/60 (2006.01); H03F 1/02 (2006.01)
CPC G11B 5/6029 (2013.01) [G11B 5/607 (2013.01); H03F 1/0261 (2013.01)] 20 Claims
OG exemplary drawing
 
15. A low-frequency recovery circuit, comprising:
a current digital to analog converter (C-DAC);
a pair of transistors arranged as a high-impedance structure and coupled to the C-DAC;
a pair of resistors having a resistance value equal to half a resistance of a resistive sensor, the pair of resistors arranged between the pair of transistors and coupled to the C-DAC, the resistive sensor used to measure a fly height of a hard disk drive; and
a gain circuit coupled to shared nodes between the pair of transistors and the pair of resistors, the low-frequency recovery circuit configured to extract and amplify a low-frequency component of a sensing signal of the resistive sensor, the sensing signal indicating the fly height.