公开(公告)号：US5214641A

公开(公告)日：1993-05-25

申请号：US758347

申请日：1991-09-09

申请人： Ching-Siang Chen ,  Bert White

发明人： Ching-Siang Chen ,  Bert White

IPC分类号： H04J1/05 ,  H04L5/06

CPC分类号： H04J1/05 ,  H04L5/06

摘要： A secondary channel FSK modem for use with primary channel QAM modems is described. The present invention is a fully integrated 75 bps narrowband secondary channel FSK modem which may be utilized with a primary channel QAM modem at data rates up to 19.2 kbps. The present invention applies switched capacitor circuits to implement band split filters and FSK transmitters. A micro-digital signal processor is implemented to realize the FSK receiver to achieve higher performance, long-term stability and versatility. The present invention provides 40 Hz separation of two carrier frequencies to improve bandwidth efficiency. In operation, an FSK modulator is combined with a highpass filter and delay equalizer to separate a section of the main channel bandwidth for use with the secondary channel. The FSK signal and QAM signal are then summed and provided to a smoothing filter for transmission line output. For receiving, an anti-alias filter recovers the received line signal and couples the signal to a highpass filter and bandpass filter. The highpass filter signal is delay equalized and coupled to a smoothing filter to obtain the main channel output. The bandpass filter is coupled through an A/D converter and to a micro-digital signal processor to recover the FSK data.

摘要翻译： 描述了与主信道QAM调制解调器一起使用的辅助信道FSK调制解调器。 本发明是一种完全集成的75bps的窄带二级信道FSK调制解调器，其可以以高达19.2kbps的数据速率与主信道QAM调制解调器一起使用。 本发明应用开关电容电路来实现频带分离滤波器和FSK发射机。 实现微数字信号处理器实现FSK接收机，实现更高的性能，长期的稳定性和多功能性。 本发明提供了两个载波频率的40Hz间隔以提高带宽效率。 在操作中，FSK调制器与高通滤波器和延迟均衡器组合以分离主信道带宽的一部分以用于辅助信道。 然后将FSK信号和QAM信号相加并提供给用于传输线输出的平滑滤波器。 为了接收，抗混叠滤波器恢复接收到的线路信号，并将信号耦合到高通滤波器和带通滤波器。 高通滤波器信号被延迟均衡并耦合到平滑滤波器以获得主通道输出。 带通滤波器通过A / D转换器耦合到微数字信号处理器以恢复FSK数据。

公开(公告)号：US06628096B1

公开(公告)日：2003-09-30

申请号：US09664248

申请日：2000-09-18

申请人： Ching-Siang Chen

发明人： Ching-Siang Chen

IPC分类号： H02K2300

CPC分类号： H02P6/08 ,  G11B19/28 ,  H02P6/12 ,  H02P2209/07

摘要： A circuit and method for providing drive currents to a polyphase dc motor are presented. The circuit (40) includes a circuit for generating a user-defined waveform first. signal in synchronism with a reference frequency signal. A reference frequency signal generator (62) generates pulses of a second signal at a reference frequency. A commutation circuit (56) combines segments of the first and second signals, and a circuit (64) is provided for applying the combined sinusoidal/trapezoidal waveforms to coils of the polyphase dc motor in a commutative sequence. Preferably, the user-defined waveform, when combined with the second signal, has approximately a sinusoidal/trapezoidal waveform.

摘要翻译： 提出了一种用于向多相直流电动机提供驱动电流的电路和方法。 电路（40）包括用于首先产生用户定义的波形的电路。 信号与参考频率信号同步。 参考频率信号发生器（62）以参考频率产生第二信号的脉冲。 换向电路（56）组合第一和第二信号的段，并且提供电路（64）用于将组合的正弦/梯形波形以交换顺序施加到多相直流电动机的线圈。 优选地，当与第二信号组合时，用户定义的波形具有大致正弦/梯形波形。

公开(公告)号：US06188192B1

公开(公告)日：2001-02-13

申请号：US09364518

申请日：1999-07-30

申请人： Ching-Siang Chen

发明人： Ching-Siang Chen

IPC分类号： G11B554

CPC分类号： G11B21/12 ,  G11B5/012 ,  H02P25/034

摘要： A disk drive system including a disk having a magnetic surface and suppported for rotation on a spindle, a magnetic head being movable relative to the magnetic surface, and a spindle motor for driving the spindle. The motor generates a back-EMF voltage during an emergency condition and switches said back-EMF voltage during said emergency condition. A comparator circuit compares different phases of back-EMF voltage, and a control circuit controls said plurality of switches to supply said back-EMF voltage to direct said head to a stored position.

摘要翻译： 一种磁盘驱动器系统，包括具有磁性表面并被支撑在主轴上的磁盘的磁盘，磁头可相对于磁性表面移动，以及用于驱动主轴的主轴电机。 电机在紧急情况下产生反电动势电压，并在所述紧急情况下切换所述反电动势电压。 比较器电路比较反电动势电压的不同相位，并且控制电路控制所述多个开关以提供所述反电动势电压以将所述磁头引导到存储位置。

公开(公告)号：US5773991A

公开(公告)日：1998-06-30

申请号：US801441

申请日：1997-02-18

申请人： Ching-Siang Chen

发明人： Ching-Siang Chen

IPC分类号： G01R19/00 ,  H02P7/00 ,  G01R23/00

CPC分类号： G01R19/0092 ,  H02P7/04

摘要： A circuit is used for sensing motor current. This circuit maximizes the power delivered to the motor whose current is being sensed. Further, this circuit results in maximum voltage drop across the motor. This circuit implements a mirrored H-bridge to mirror a current flowing through a conventional H -bridge having a sensing resistor in series with a VCM motor. The voltage drop across the sensing resistor serves as an indication of the current flowing

摘要翻译： 电路用于检测电机电流。 该电路使传递到电流的电机的功率最大化。 此外，该电路导致电动机上的最大电压降。 该电路实现了镜像H桥，以反映流过具有与VCM电动机串联的感测电阻器的常规H桥的电流。 感测电阻上的电压降用作电流流动的指示

公开(公告)号：US06268772B1

公开(公告)日：2001-07-31

申请号：US09440488

申请日：1999-11-15

申请人： Ching-Siang Chen

发明人： Ching-Siang Chen

IPC分类号： H03F304

CPC分类号： H03F3/347 ,  H03F3/3008 ,  H03F3/345

摘要： A slew rate controlled power amplifier (112) for use in a dc motor driver circuit is presented. The amplifier (112) has a power transistor (72) connected to control a drive current (IMOTOR) in a phase of the dc motor with which it is associated and to develop an output voltage (VOUT) on the phase in accordance with the drive current (IMOTOR). A mirror transistor (74) is connected to establish the ratioed magnitude of the current in the power transistor (72), and a feedback circuit (90) is connected to controllably feed back the output voltage (VOUT) to the mirror transistor (74) to control the drive current (IMOTOR). A commutatively operated slew-rate control circuit (57,58) is connected to the feedback circuit (90) to control the drive current (IMOTOR). By coupling the feedback from the phase voltage, VOUT, into the current loop the loop stability is greatly improved and oscillations on the output phase voltage are reduced or eliminated. The circuit may also have a voltage-equalizing transistor (78) in series with the mirror transistor (74) and a differential amplifier (85) to develop a bias voltage to the voltage-equalizing transistor (78) based on the difference between the output voltage and a voltage in the mirror current flowpath. By equalizing the output and current mirror flowpath voltages, the linearity of the power amplifier is greatly improved during current slew.

摘要翻译： 提出了一种用于直流电机驱动电路的转换速率控制功率放大器（112）。 放大器（112）具有功率晶体管（72），功率晶体管（72）被连接以控制与其相关联的直流电动机的相位中的驱动电流（IMOTOR），并且根据驱动器在相位上产生输出电压（VOUT） 当前（IMOTOR）。 连接镜面晶体管（74）以建立功率晶体管（72）中的电流的比值大小，并且连接反馈电路（90）以将输出电压（VOUT）可控地反馈到反射镜晶体管（74） 以控制驱动电流（IMOTOR）。 交流运算的转换速率控制电路（57,58）连接到反馈电路（90）以控制驱动电流（IMOTOR）。 通过将来自相电压VOUT的反馈耦合到电流环中，环路稳定性大大提高，并且减小或消除了输出相电压的振荡。 电路还可以具有与镜晶体管（74）串联的电压均衡晶体管（78）和差分放大器（85），以根据输出端之间的差异向电压均衡晶体管（78）产生偏置电压 电流和电流在镜面电流流路。 通过均衡输出和电流镜流路电压，在电流转换期间功率放大器的线性度大大提高。

公开(公告)号：US5907258A

公开(公告)日：1999-05-25

申请号：US634098

申请日：1996-04-17

申请人： Ching-Siang Chen

发明人： Ching-Siang Chen

IPC分类号： G01P15/18 ,  H03H11/12 ,  H04B1/10

CPC分类号： H03H11/12 ,  G01P15/18

摘要： The present invention discloses a fully integrated precision HDA shock sense circuit with high-order filters implemented in integrated circuit technology. Filters are integrated with an improved on-chip bias generator so that they can provide stable, trimmable and/or programmable frequency responses with a minimum number of external capacitors. The invention provides dual full-wave rectifiers for X-axis and Y-axis shock sensing so that more accurate and reliable shock detection can be achieved. Input signals from X-axis and Y-axis shock sensors are converted to current and provided to the dual full-wave rectifiers. The currents thus full-wave rectified are summed and lowpass filtered to generate an output signal, which is then fed to a comparator to produce a shock detection logic signal.

摘要翻译： 本发明公开了一种采用集成电路技术实现的高阶滤波器的全集成精密HDA冲击检测电路。 滤波器与改进的片上偏置发生器集成，使得它们可以使用最少数量的外部电容器提供稳定的可调节和/或可编程的频率响应。 本发明提供用于X轴和Y轴冲击感测的双全波整流器，从而可以实现更准确可靠的冲击检测。 X轴和Y轴冲击传感器的输入信号转换为电流并提供给双全波整流器。 因此，全波整流的电流被相加和低通滤波以产生输出信号，然后将该信号馈送到比较器以产生冲击检测逻辑信号。