公开(公告)号：EP1865505A1

公开(公告)日：2007-12-12

申请号：EP06425391.7

申请日：2006-06-09

Applicant: STMicroelectronics S.r.l.

Inventor： Maiocchi, Giuseppe ,  Galbiati, Ezio ,  Boscolo Berto, Michele

IPC: G11B15/18 ,  H02P7/00 ,  H02P6/08

CPC classification number: G11B5/02 ,  G11B5/022 ,  G11B2005/001 ,  H02P25/034

Abstract: Usually the control power signal lines of a positioning voice coil motor (VCM), driven in a PWM or PSM mode, and the relatively low power signal lines of a read/write (R/W) head runs parallel to each others along a unique flat cable that connects the VCM moved arm carrying the head to the related drive control and signal processing circuitries of a disk storage device. When controlling the VCM at relatively low current levels, both PSM drive signals approach the 50% duty cycle and therefore the PSM commutations become so close each others that may practically be considered concurrent. In these conditions of operation, switching energies sum and reach a level that may be sufficient to inject switching noise from the VCM power lines in adjacent low level signals lines of the connection flat cable.
A way of preventing concurrent commutations of a pair of PSM drive signals of an output bridge stage driving a voice coil motor (VCM), consists in establishing a certain threshold level of programmed current to be forced the voice coil motor and when the level of the programmed current to be forced through the voice coil motor drops below said threshold, enhancing the time offset between commutation edges of the two PSM drive signals by a certain minimum time. This is accomplished either by phase shifting one of the signals from the other signal or by broadening the width of the pulses of one of the two PSM drive signals and by narrowing the width of the pulses of the other PSM drive signal, while maintaining constant the individual duty-cycle of each drive signal.

Abstract translation: 通常在PWM或PSM方式驱动的定位的音圈电机（VCM），和一个读/写的相对低功率的信号线（R / W）磁头平行于彼此沿一个唯一的功率控制信号线 扁平电缆连接VCM并移动臂承载头到磁盘存储装置的相关驱动控制和信号处理电路系统。 当控制在相对较低的电流水平的VCM，这两个PSM驱动信号接近50％的占空比，因此PSM减刑变得如此接近eachothers也几乎可以被认为是并发的。 在操作中的合成条件，交换能量求和并达到一个电平都可以足以注入从在连接扁平电缆的相邻低电平的信号线的电力线VCM开关噪声。 防止一对输出桥级驱动的音圈电动机（VCM）的PSM驱动信号的同时换向，besteht在建立编程电流的某个阈值电平的方式被强制音圈电机和时的水平 编程电流通过音圈马达降到低于所述阈值被强制，从而增强时间由某最小时间两个PSM驱动信号的换向边缘之间的偏移量。 这是通过相移与其它信号的信号的一个或一个通过加宽两个PSM驱动信号中的一个的脉冲的宽度和通过缩小其它PSM驱动信号的脉冲的宽度来实现无论哪种，同时保持恒定的 每个驱动信号的各个占空比。