• JSTS:Journal of Semiconductor Technology and Science
• /
• v.2 no.3
• /
• pp.197-204
• /
• 2002

DRAM, SRAM, and FLASH memory are three major memory devices currently used in most electronic applications. But, they have very distinct attributes, therefore, each memory could be used only for limited applications. MRAM (Magneto-resistive Random Access Memory) is a promising candidate for a universal memory that meets all application needs with non-volatile, fast operational speed, and low power consumption. The simplest architecture of MRAM cell is a series of MTJ (Magnetic Tunnel Junction) as a data storage part and MOS transistor as a data selection part. To be a commercially competitive memory device, scalability is an important factor as well. This paper is testing the actual electrical parameters and the scaling factors to limit MRAM technology in the semiconductor based memory device by an actual integration of MRAM core cell. Electrical tuning of MOS/MTJ, and control of resistance are important factors for data sensing, and control of magnetic switching for data writing.

• Journal of Sensor Science and Technology
• /
• v.18 no.5
• /
• pp.393-401
• /
• 2009

This paper describes development of a new displacement sensor for intelligent suspension system in which the damping force has been controlled by MR fluid. Most of the current vehicle height sensors have been installed at external place of the damper and connected to that by mechanical linkages so far. The developed sensor has a new mechanism which detects movement of the sensor rod same as connecting rod in the suspension damper by using a GMR Sensor and converts it to the relative displacement from an initial position.

• Journal of Magnetics
• /
• v.7 no.3
• /
• pp.101-105
• /
• 2002

MRAM (Magnetoresistive Random Access Memory) is a promising candidate for a universal memory that meets all application needs with non-volatile, fast operational speed, and low power consumption. The simplest architecture of MRAM cell is a series of MTJ (Magnetic Tunnel Junction) as a data storage part and MOS transistor as a data selection part. This paper is for testing the actual electrical parameters to adopt MRAM technology in the semiconductor based memory device. The discussed topics are an actual integration of MRAM core cell and its properties such as electrical tuning of MOS/MTJ for data sensing and control of magnetic switching for data writing. It will be also tested that limits of the MRAM technology for a high density memory.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.16 no.1 s.106
• /
• pp.75-80
• /
• 2006

This paper introduces the mechanism of the ESD(electrostatic discharge) in the HDD spindle system using FDBs(fluid dynamic bearings). When a HDD(hard disk drive) spindle system is rotating, triboelectric charging occurs in the FDBs through the friction between the lubricant and the rotating shaft or between the lubricant and stationary sleeve. And this electrostatic charge is accumulated in the rotating parts of the HDD spindle system because they are insulated from the ground by the lubricant. This research shows experimentally that the behavior of electric charge and discharge in the FDB spindle system is the same as that of a capacitor. It also measures the electrostatic voltage difference between the rotating and stationary parts in the FDB spindle system due to the change of humidity, supporting load and motor speed. This research shows that the control of ESD is required in the HDD spindle system using FDBs, because the electrostatic charge accumulated in the FDB spindle system may cause the breakdown damage of the GMR head and data loss consequently.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.11a
• /
• pp.318-323
• /
• 2005

This paper introduces the mechanism of the ESD (Electrostatic discharge) in the HDD spindle system using FDBs (Fluid Dynamic Bearings). When a HDD (Hard Disk Drive) spindle system is rotating, triboelectric charging occurs in the FDBs through the friction of the lubricant between the rotating shaft and stationary sleeve. And this electrostatic charge is accumulated in the rotating part of the HDD spindle system because it is insulated from the ground by the lubricant. This research shows experimentally that the behavior of electric charge and discharge in the FDB spindle system is the same as that of a capacitor. It also measures the electrostatic charge and discharge of the FDB spindle system due to the chanse of humidity, supporting load and motor speed. This research shows that the control of ESD is required in the HDD spindle system using FDBs, because the electrostatic charge accumulated in the FDB spindle system may cause the breakdown damage of the GMR head and data loss consequently.