Invention Grant
- Patent Title: Write data protection at emergency power off
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Application No.: US16831004Application Date: 2020-03-26
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Publication No.: US10996740B2Publication Date: 2021-05-04
- Inventor: Hiroki Watanabe , Gaku Ikedo , Naoyuki Kagami , James Jinshi Ng , Brian Kenneth Tanner
- Applicant: Western Digital Technologies, Inc.
- Applicant Address: US CA San Jose
- Assignee: Western Digital Technologies, Inc.
- Current Assignee: Western Digital Technologies, Inc.
- Current Assignee Address: US CA San Jose
- Agency: Patterson & Sheridan, LLP
- Agent Steven H. Versteeg
- Main IPC: G06F1/3296
- IPC: G06F1/3296 ; G11B19/20 ; G06F3/06 ; G06F1/3287 ; H02P6/08 ; H02P6/18 ; H02P6/182

Abstract:
The present disclosure generally relates to an electronic circuit and method of operating thereof to back up write cache data on DDR memory in data storage devices during an emergency power off (EPO). The method involves using a power management integrated circuit (PMIC), a combo driver and one MOSFET for regulator output. The method involves detecting a voltage value that is below a predetermined threshold value, retracting a write head away from a hard disk drive (HDD), backing up data, and then resetting the HDD after the backup is complete. The backing up and retraction may occur in parallel or in sequence. The method utilizes the spindle back-electromotive force (BEMF) power to have sufficient power to make the backup. If the power from the spindle BEMF is too low, then the retraction is suspended and a high impedance is present to lighten the load until the BEMF recovers before the power on reset. As such, the back-up data is not reset and volatized by a lack of power.
Public/Granted literature
- US20200225733A1 WRITE DATA PROTECTION AT EMERGENCY POWER OFF Public/Granted day:2020-07-16
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