公开(公告)号：US06134060A

公开(公告)日：2000-10-17

申请号：US872809

申请日：1997-06-10

Applicant: Marc H. Ryat

Inventor： Marc H. Ryat

IPC: G11B5/09 ,  G01R33/09 ,  G11B5/00 ,  G11B5/012 ,  G11B5/02 ,  G11B33/12

CPC classification number: G01R33/09 ,  G11B5/012 ,  G11B5/02 ,  G11B2005/0018 ,  G11B33/122

Abstract: A current bias, current sense magneto-resistive preamplifier for a hard disk drive and related methods preferably includes an MR sensor responsive to a current bias for sensing a change in magnetic data flux and responsively providing a change in electrical resistance. A preamplifying circuit is preferably connected to the MR sensor for providing the current bias thereto and for amplifying a detected change in electrical resistance. The preamplifying circuit includes a sensor biasing circuit for providing the current bias to the MR sensor and an amplifying output circuit for providing an amplified output signal representative of the detected change in current bias to the MR sensor. The sensor biasing circuit preferably includes a current source, a first amplifying circuit connected to the MR sensor for sensing the change in electrical resistance therefrom, and a second amplifying circuit having a first input connected to the first amplifying circuit and a second input connected to the current source. The sensor biasing circuit also includes a transconductance amplifying circuit connected to first and second outputs of the second amplifying circuit and having an output connected to the first amplifying circuit for providing an output current proportional to the voltage difference at the first and second inputs thereof. The preamplifier further includes a capacitor connected to the preamplifying circuit for providing stability to at least a portion of the preamplifying circuit.

Abstract translation: 用于硬盘驱动器的电流偏置电流感测磁阻前置放大器和相关方法优选地包括响应于电流偏压的MR传感器，用于感测磁数据通量的变化并且响应地提供电阻的变化。 优选地，前置放大电路连接到MR传感器以提供电流偏置，并用于放大检测到的电阻变化。 前置放大电路包括用于向MR传感器提供电流偏置的传感器偏置电路和用于向MR传感器提供表示检测到的电流偏置变化的放大输出信号的放大输出电路。 传感器偏置电路优选地包括电流源，连接到MR传感器的用于感测电阻变化的第一放大电路，以及具有连接到第一放大电路的第一输入端的第二放大电路和连接到第一放大电路的第二输入端 当前来源。 传感器偏置电路还包括连接到第二放大电路的第一和第二输出并具有连接到第一放大电路的输出的跨导放大电路，用于提供与其第一和第二输入处的电压差成比例的输出电流。 前置放大器还包括连接到前置放大电路的电容器，用于向前置放大电路的至少一部分提供稳定性。

公开(公告)号：US6118611A

公开(公告)日：2000-09-12

申请号：US948209

申请日：1997-10-09

Applicant: Hidekazu Shibasaki ,  Hiroaki Ueno ,  Ken Yakuwa

Inventor： Hidekazu Shibasaki ,  Hiroaki Ueno ,  Ken Yakuwa

IPC: G11B5/00 ,  G11B5/02 ,  G11B19/02 ,  G11B5/09

CPC classification number: G11B5/02 ,  G11B19/02 ,  G11B2005/0016 ,  G11B2005/0018

Abstract: A signal reproducing circuit for a magneto-resistive effect head includes a constant current source for supplying a sense current to an MR head in a read state, first constant current sources for supplying first constant currents to a pair of reproduction transistors in the read state, and a capacitor connected between the emitters of the transistors. Furthermore, second constant current sources for supplying second constant currents are connected in parallel with the first constant current sources. Control is given so that when switching an idle state to the read state is commanded, the second constant current sources remain on for a given period of time. Owing to this circuitry, a transient period during which the idle state is switched to the read state or a transient period during which heads are switched in the read state can be shortened to a great extent. Consequently, superposition of an unwanted offset component on a reproduced signal can be suppressed, and a loss in data-handling capacity can be minimized.

Abstract translation: 用于磁阻效应头的信号再现电路包括用于在读取状态下向MR磁头提供感测电流的恒流源，用于在读取状态下向一对再现晶体管提供第一恒定电流的第一恒定电流源， 以及连接在晶体管的发射极之间的电容器。 此外，用于提供第二恒定电流的第二恒流源与第一恒定电流源并联连接。 给出控制，使得当将空闲状态切换到读取状态时，第二恒定电流源保持打开一段给定的时间。 由于该电路，可以在很大程度上缩短空闲状态切换到读取状态的过渡时段或读取状态期间磁头切换的过渡时段。 因此，可以抑制再现信号上的不需要的偏移分量的叠加，并且可以最小化数据处理能力的损失。

公开(公告)号：US6111716A

公开(公告)日：2000-08-29

申请号：US23510

申请日：1998-02-13

Applicant: Tuan V. Ngo ,  Craig M. Brannon ,  Douglas R. Peterson

Inventor： Tuan V. Ngo ,  Craig M. Brannon ,  Douglas R. Peterson

IPC: G11B5/00 ,  G11B5/012 ,  G11B5/02 ,  G11B5/035 ,  G11B33/12

CPC classification number: G11B5/02 ,  G11B5/012 ,  G11B2005/0016 ,  G11B2005/0018 ,  G11B33/122 ,  G11B5/035

Abstract: A magnetoresistive sensor and preamplifier system for sensing magnetization patterns in a magnetic disk based digital data storage and retrieval memory with a grounded magnetoresistive sensor The signals from the magnetoresistive sensor are coupled by a coupling capacitor to a grounded differential amplifier. The structure of the coupling capacitor in a monolithic integrated circuit determines the passband for the system in passing the magnetoresistive sensor signals.

Abstract translation: 用于利用接地磁阻传感器感测基于磁盘的数字数据存储和检索存储器中的磁化模式的磁阻传感器和前置放大器系统来自磁阻传感器的信号通过耦合电容耦合到接地差分放大器。 单片集成电路中的耦合电容器的结构决定了传递磁阻传感器信号时系统的通带。

公开(公告)号：US6104563A

公开(公告)日：2000-08-15

申请号：US16551

申请日：1998-01-30

Applicant: Moris M. Dovek ,  Gang Herbert Lin ,  Erhard T. Schreck

Inventor： Moris M. Dovek ,  Gang Herbert Lin ,  Erhard T. Schreck

IPC: G11B5/00 ,  G11B5/012 ,  G11B5/02 ,  G11B5/09 ,  G11B5/596 ,  G11B19/04 ,  G11B5/03

CPC classification number: G11B19/04 ,  G11B5/012 ,  G11B5/02 ,  G11B2005/0018 ,  G11B5/09 ,  G11B5/59683

Abstract: A magnetic storage system capable of separating thermal signals from data signals is disclosed. The magnetic storage system includes a magnetic media and a head associated with the magnetic media. The head includes a magneto-resistive element which is biased by a modulated bias current. The modulated bias current modulates thermal signals to a first frequency and modulates data signals to at least a second frequency. A method of separating thermal signals from data signals read from a magnetic storage media is also disclosed. The method includes the steps of (1) providing a head for reading information from the magnetic storage media, the head having an MR element; and, (2) biasing the MR element with a modulated bias current.

Abstract translation: 公开了一种能够从数据信号分离热信号的磁存储系统。 磁存储系统包括磁介质和与磁介质相关联的磁头。 磁头包括被调制的偏置电流偏置的磁阻元件。 调制的偏置电流将热信号调制到第一频率，并将数据信号调制到至少第二频率。 还公开了从磁存储介质读取的数据信号中分离热信号的方法。 该方法包括以下步骤：（1）提供用于从磁存储介质读取信息的磁头，磁头具有MR元件; 和（2）用调制的偏置电流偏置MR元件。

公开(公告)号：US6078453A

公开(公告)日：2000-06-20

申请号：US967123

申请日：1997-11-12

Applicant: Rich A. Dziallo ,  Mark Hagen

Inventor： Rich A. Dziallo ,  Mark Hagen

IPC: G11B5/00 ,  G11B5/012 ,  G11B5/55 ,  G11B5/596 ,  G11B5/02

CPC classification number: G11B5/59605 ,  G11B5/012 ,  G11B5/5534 ,  G11B5/59633 ,  G11B2005/0013 ,  G11B2005/0018 ,  G11B5/5547

Abstract: A method of deriving optimum read channel parameters for use in reading servo sector data from a disk drive having a head mounted on an actuator, a read channel including a preamplifier, a disk having a plurality of tracks, each track having multiple sequentially active servo sectors, a sampled signal head positioning servo controller to control the actuator position, a microprocessor, and a memory. The first step is to store default values and variable test values associated with read channel parameters. The microprocessor is programmed to detect certain servo errors which may occur. The read channel parameters are initially set to the default values in order to ensure that the disk drive can properly perform a seek. A series of seeks is then performed in alternating directions over a band of tracks. While performing the seeks, one of the read channel parameters is set to one of the variable test values for a first set of alternating servo sectors; next, the read channel parameters are set back to their default values for a second set of alternating servo sectors; and servo errors which occur during the series of seeks are recorded. This process is repeated for each of a predetermined matrix of test values. At the end, each of the read channel parameter values resulting in the least errors logged is identified as being optimal, and a table of optimized read channel parameter values is stored in the disk drive.

Abstract translation: 一种导出用于从具有头部安装在致动器上的磁盘驱动器读取伺服扇区数据的最佳读取通道参数的方法，包括前置放大器的读取通道，具有多个磁道的磁盘，每个磁道具有多个顺序有效的伺服扇区 ，采样信号头定位伺服控制器来控制致动器位置，微处理器和存储器。 第一步是存储与读通道参数相关联的默认值和变量测试值。 微处理器被编程为检测可能发生的某些伺服误差。 读通道参数最初设置为默认值，以确保磁盘驱动器可以正确执行查找。 然后在一条轨道上的交替方向上执行一系列寻道。 在执行寻道时，将读取通道参数中的一个设置为第一组交替伺服扇区的可变测试值之一; 接下来，将读取的通道参数设置回第二组交替伺服扇区的默认值; 并且记录在一系列寻找期间发生的伺服误差。 针对测试值的预定矩阵中的每一个重复该过程。 最后，将记录的最少错误的每个读取通道参数值标识为最佳，并且将优化的读取通道参数值的表存储在磁盘驱动器中。

公开(公告)号：US6069762A

公开(公告)日：2000-05-30

申请号：US350139

申请日：1999-07-09

Applicant: Hajime Aoi ,  Toshiaki Tsuyoshi ,  Makoto Koizumi ,  Nobumasa Nishiyama ,  Yoshibumi Matsuda ,  Takuji Ogawa ,  Kazuhisa Shiraishi

Inventor： Hajime Aoi ,  Toshiaki Tsuyoshi ,  Makoto Koizumi ,  Nobumasa Nishiyama ,  Yoshibumi Matsuda ,  Takuji Ogawa ,  Kazuhisa Shiraishi

IPC: G11B5/02 ,  G11B5/00 ,  G11B5/012 ,  G11B5/09 ,  G11B5/39 ,  G11B5/40 ,  G11B5/55 ,  G11B5/596 ,  G11B19/02 ,  G11B19/04 ,  G11B27/30 ,  G11B27/36 ,  G11B15/12 ,  G11B5/127

CPC classification number: G11B19/04 ,  G11B19/02 ,  G11B27/3027 ,  G11B27/36 ,  G11B5/00 ,  G11B5/012 ,  G11B5/40 ,  G11B5/5547 ,  G11B2005/0016 ,  G11B2005/0018 ,  G11B5/59683

Abstract: In a magnetic recording drive having a plurality of magnetic heads each employing a magnetoresistive sensor for the purpose of averaging the time required for sense currents to be caused to flow through the respective magnetoresistive sensors to shorten the longest reproducing time and to suppress the degradation of the characteristics due to the electromigration, thereby improving the reliability of the magnetic recording drive, the magnetic recording drive includes circuits for averaging the useful life depending on the currents caused to flow through the respective magnetoresistive sensors among the plurality of magnetic heads, whereby the time required for the sense current to be caused to flow through one MR reproducing head is greatly shortened. Therefore, the levels of outputs of the MR reproducing heads can be increased without reduction of the reliability and thus the reliability of the magnetic recording drive can be improved.

Abstract translation: 在具有多个磁头的磁记录驱动器中，每个磁头采用磁阻传感器，用于平均要使感应电流流过各磁阻传感器所需的时间，以缩短最长再现时间并抑制 由于电迁移的特性，从而提高了磁记录驱动器的可靠性，磁记录驱动器包括用于根据流过多个磁头中的相应磁阻传感器的电流来平均使用寿命的电路，由此所需的时间 使得通过一个MR再现头流动的感测电流大大缩短。 因此，可以在不降低可靠性的情况下增加MR再现头的输出电平，从而可以提高磁记录驱动器的可靠性。

公开(公告)号：US6067200A

公开(公告)日：2000-05-23

申请号：US893313

申请日：1997-07-16

Applicant: Kazuhide Ohba ,  Kensuke Miyagawa ,  Hajime Miura ,  Hideki Ohmori

Inventor： Kazuhide Ohba ,  Kensuke Miyagawa ,  Hajime Miura ,  Hideki Ohmori

IPC: G11B5/39 ,  G11B5/00 ,  G11B5/012 ,  G11B5/02 ,  G11B5/035 ,  G11B5/455 ,  G11B5/03

CPC classification number: G11B5/455 ,  G11B5/012 ,  G11B5/02 ,  G11B5/035 ,  G11B2005/0018

Abstract: A method is provided to adjust a bias current flowing through a magneto-resistive effect type magnetic head. An examining current is supplied to the magneto-resistive effect type magnetic head, and a voltage applied to a pair of terminals of the magneto-resistive effect type magnetic head is measured. In addition, a resistance of the magneto-resistive effect type magnetic head is calculated according to the examining current and the voltage, and an allowable range of the bias current flowing through the magneto-resistive effect type magnetic head is determined according to a relationship between a life time of the magneto-resistive effect type magnetic head examined in advance and the resistance of the magneto-resistive effect type magnetic head. An optimum bias current is determined within the allowable range in condition that a slice level margin is maximized.

Abstract translation: 提供了一种调节流过磁阻效应型磁头的偏置电流的方法。 检查电流被提供给磁阻效应型磁头，并且测量施加到磁阻效应型磁头的一对端子的电压。 此外，根据检查电流和电压计算磁阻效应型磁头的电阻，并且流过磁阻效应型磁头的偏流的容许范围根据 提前检查磁阻效应型磁头的寿命和磁阻效应型磁头的电阻。 在限幅电平裕度最大化的条件下，在容许范围内确定最佳偏置电流。

公开(公告)号：US6057972A

公开(公告)日：2000-05-02

申请号：US950131

申请日：1997-10-14

Applicant: Gregg Romeo Castellucci

Inventor： Gregg Romeo Castellucci

IPC: G01R33/09 ,  G11B5/00 ,  G11B5/012 ,  G11B5/02 ,  G11B19/04 ,  G11B5/09 ,  G11B5/03

CPC classification number: G11B19/04 ,  G01R33/09 ,  G11B5/012 ,  G11B5/02 ,  G11B2005/0018

Abstract: A low noise current source circuit is disclosed for biasing a magnetoresistive (MR) read head. The current source comprises a field-effect transistor (FET) cascoded to a second transistor which, in turn, is coupled to the MR element. A filter device including a capacitor is coupled across the gate-source junction of the FET, and a sensing device, such as a resistor, is coupled to the gate of the FET for detecting current flowing into said capacitor. Boost circuitry, coupled to the sensing device, boosts the charge/discharge rate of the filter capacitor when the voltage of the sensing device exceeds a certain threshold.

Abstract translation: 公开了一种用于偏置磁阻（MR）读头的低噪声电流源电路。 电流源包括级联到第二晶体管的场效应晶体管（FET），其又耦合到MR元件。 包括电容器的滤波器装置跨过FET的栅极 - 源极结耦合，并且诸如电阻器的感测装置耦合到FET的栅极，以检测流入所述电容器的电流。 耦合到感测装置的升压电路在感测装置的电压超过一定阈值时提高滤波电容器的充电/放电速率。

公开(公告)号：US6028730A

公开(公告)日：2000-02-22

申请号：US12055

申请日：1998-01-22

Applicant: Kunihiko Ishihara

Inventor： Kunihiko Ishihara

IPC: G11B5/39 ,  G11B5/00 ,  G11B5/465 ,  H01F10/32 ,  H01F41/30 ,  G11B5/455

CPC classification number: B82Y25/00 ,  B82Y40/00 ,  G11B5/00 ,  H01F10/3268 ,  H01F41/302 ,  G11B2005/0008 ,  G11B2005/0018 ,  G11B5/3967 ,  G11B5/465

Abstract: The present invention provides a device for supplying an initialization pulse current to at least laminations of a pinned ferromagnetic layer, a non-magnetic metal layer and a free ferromagnetic layer in a magnetoresistive transducer in an initialization pulse current direction which is perpendicular to a predetermined magnetization direction of the pinned ferromagnetic layer and also parallel to an interface between the pinned ferromagnetic layer and the non-magnetic metal layer, wherein the device is electrically connected to opposite ends of the laminations spaced from each other in the initialization current direction for applying a pulse voltage between the opposite ends so as to flow the initialization pulse current in the initialization pulse current direction through the laminations.

Abstract translation: 本发明提供一种用于在初始化脉冲电流方向上的磁阻换能器中的至少一个钉扎铁磁层，非磁性金属层和自由铁磁层的叠层的初始化脉冲电流的装置，该初始化脉冲电流方向垂直于预定的磁化 被钉扎的铁磁层的方向并且还平行于被钉扎的铁磁层和非磁性金属层之间的界面，其中该器件在初始化电流方向上彼此间隔地电连接到叠片的相对端，以施加脉冲 电压在相对端之间，以便使初始化脉冲电流方向上的初始化脉冲电流流过叠片。

公开(公告)号：US6005733A

公开(公告)日：1999-12-21

申请号：US873762

申请日：1997-06-12

Applicant: Robert J. Schuelke ,  Crispin K. Metzler

Inventor： Robert J. Schuelke ,  Crispin K. Metzler

IPC: G11B5/00 ,  G11B5/012 ,  G11B5/02 ,  G11B5/40

CPC classification number: G11B5/012 ,  G11B5/02 ,  G11B5/40 ,  G11B2005/0018

Abstract: A preamplifier bias circuit for use in an AC coupled magnetoresistive read head amplifier which includes a pair of head contacts, a pair of amplifier inputs, a pair of coupling capacitors and a means for selectively shunting the amplifier inputs and rapidly charge the coupling capacitors. The pair of head contacts and the pair of amplifier inputs couple the preamplifier bias circuit to a magnetoresistive element and a read amplifier, respectively. Each of the coupling capacitors is connected between one of the head contacts and one of the amplifier inputs to block a static potential across the magnetoresistive element. The means for selectively shunting the amplifier inputs selectively provides a low impedance path to rapidly charge the coupling capacitors and clamps the amplifier inputs to a known potential. By selectively providing a low impedance path, the AC coupled magnetoresistive read head amplifier can be protected and its associated delay time prior to operation can be decreased.

Abstract translation: 一种用于交流耦合磁阻读出头放大器中的前置放大器偏置电路，其包括一对头部触点，一对放大器输入端，一对耦合电容器和用于选择性地分流放大器输入并快速对耦合电容器充电的装置。 一对头部接点和一对放大器输入将前置放大器偏置电路分别耦合到磁阻元件和读取放大器。 耦合电容器中的每一个连接在头部触点中的一个和放大器输入中的一个之间，以阻挡磁阻元件两端的静电势。 用于选择性地分流放大器输入的装置选择性地提供低阻抗路径以快速地对耦合电容充电并将放大器输入钳位到已知电位。 通过选择性地提供低阻抗路径，可以保护AC耦合磁阻读头放大器，并且可以减少其在操作之前的相关联的延迟时间。