Apparatus and method for writing to magnetic media using an AC bias current to enhance the write field

US10643642B2 · kind B2 · utility

Assignee

• Western Digital Technologies, Inc. · US

Inventors

• Gonçalo Marcos Baião De Albuquerque · San Jose, US
• Yunfei Ding · Milpitas, US
• Alexander Goncharov · معلمی نژاد, US
• Kuok San Ho · Emerald Hills, US
• Daniele Mauri · San Jose, US
• Goran Mihajlovic · San Jose, US
• Suping Song · Fremont, US
• Petrus Antonius Van Der Heijden · San Jose, US

Key dates

• Filing date: Jul 1, 2019
• Grant date: May 5, 2020
• Expiry date: Jul 1, 2039

Classification

• Technology area (CPC G): Physics
• CPC primary: G11B2005/0024
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

An apparatus comprises a main pole, a trailing shield, a write-field-enhancing structure, a write coil, a write current control circuit configured to supply a write current to the write coil to record a bit to a magnetic medium, and a driving current control circuit configured to supply a driving current to the write-field-enhancing structure, wherein the driving current comprises a driving pulse, and wherein the driving current comprises an AC component with a duty cycle selected based at least in part on a power constraint. A method of writing to a magnetic medium comprises supplying a write current to a write coil of a magnetic write head, and supplying a driving current to a free layer disposed in a write gap between a main pole and a trailing shield, wherein the driving current comprises an AC component with a duty cycle based at least in part on a power constraint.