The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 13, 2012
Filed:
Feb. 27, 2009
Julio Enrique Ayala, Ii, Wylie, TX (US);
Juergen Luebbe, Plano, TX (US);
Julio Enrique Ayala, II, Wylie, TX (US);
Juergen Luebbe, Plano, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A system for implementing current shaping for retract of a voice coil motor (VCM) includes drive circuitry coupled to drive the VCM according to a logic state of the system. Current shaping circuitry is configured to temporarily decrease the bandwidth of a VCM transconductance loop in response to a control signal. The transconductance loop includes at least the VCM, the current shaping circuitry and the drive circuitry. The system also includes logic configured to provide the control signal at an end portion a drive logic state to enter a current shaping logic state as a transition from the drive logic state to a floating logic state to reduce current through the VCM such that acoustic emissions from the VCM are mitigated during the retract.