L6470无法达到大于700步/秒的步进速率

亲爱的汽车IC论坛：


我正在使用L6470来驱动连接到变速箱的步进电机，并且在任何微步进设置下都无法达到大于700步/秒的步进速率。随着速度的增加，电机会响起并停转。在低于500步/秒的速度下，电机完美运行。电机的Rm为4.5欧姆。 Lm是3.6mh（规格表）。 Ke为0.143v / hz（约）。我玩过除了pmt以外的所有设置并且无法获得更快的速度。我需要大约2000步/秒。

我也在相同的设置上尝试了L6472并且没有达到所需速度的问题。问题是我还需要以1/10步进5-10步/秒的极低步进速率运行。使用L6472时，电机不够平稳且振动很大。

我需要的是L6472的高速范围和L6470的低速平滑度。所以我的问题是：

1）我是否在做一些严重错误的L6470，这使我无法达到更高的速度，这对于这款芯片来说是否正常？

2）我可以将电机连接到两个芯片并根据速度要求激活其中一个吗？我不想放置一个开关系统来切换芯片，只需将它们连接到电机上，并将一个芯片置于高阻抗状态，而我正在使用另一个芯片，即6470-1A到6472 1A到电机A等。

谢谢你的帮助，

格雷格
＃L6470-l6472



以下为原文




Dear Motor IC Forum:


I am using an L6470 to drive a stepper motor attached to a gearbox and am not able to achieve step rates greater than roughly 700 steps/sec with any microstepping setting. The motor gets loud and stalls as speeds increase. At speeds below 500 steps/sec the motor works perfectly. The Rm of the motor is 4.5 ohms. The Lm is 3.6mh (spec sheet). The Ke is 0.143 v/hz (approximately). I have played with all setting except pmt and have not been able to get more speed. I need roughly 2000 steps/sec.

I also tried the L6472 on the same setup and had no issues reaching the required speeds. The problem is I also need to run at very low step rates of 5-10 steps/second at 1/16th steps. With the L6472 the motor is not smooth enough and vibrates quite a bit.

What I need is the high speed range of the L6472 and the low speed smoothness of the L6470.  So my questions are:

1) Am I doing something radically wrong with the L6470 that is preventing me from reaching higher speeds or is this normal for this chip?

2) Can I connect the motor to both chips and activate one or the other depending on the speed requirements? I do not want to put in a switching system to switch between chips but simply connect them both to the motor and put one chip in the high impedance state while I am using the other i.e 6470-1A to 6472 1A to Motor A etc.

Thanks for your help,

Greg  
#l6470-l6472