Winding noise during hold

[ppostig]

Posted on October 25, 2013 at 00:06

Hello,

With L6472 I hear audible (high pitch) noise from motor when holding. volume of noise increase with increase hold current. It d

oes not matter if the motor is loaded or not.

When I look at winding with scope one pair is the typical pwm signal locked and duty cycle appropriate for the hold setpoint

The other pair of windings appear ‘unlocked’ and much higher in frequency than the other winding.

EVAL Bd hardware

24v supply, current set point .35amp

Nema17, 18mh / 8.9ohms, 0.9degree step angle

Is there a setting I am overlooking

This does not occur with L6470.

thanks for your support !

[Enrico Poli]

Posted on December 16, 2013 at 10:14

Hello,

The current control performance depends on the configuration of the parameters (off time, fast decay duration, etc). The default configuration of the IC should not be considered the one which gives best results. You could try the following configuration: Minimum on time = 3 us Minimum OFF time = 21 us tOFFfast = 10 us tSTEP = 12 us tsw = 44 us More details about the curren tcontrol algorithm are available in

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/application_note/DM00063976.pdf

Kind Regards Enrico

[fab]

Posted on May 29, 2014 at 18:08

Dear Enrico,

I have the same problem ofthe other customer;I find thisproblemwith two different family of sanyo denki's stepper motor (you can find the datasheet in the attachment): Type 103H7126-0140 and Type 103H7123-0140;

I tried

your suggested configuration but the noise still remain;

I have tryed the configuration suggested in document UM1688 pag.39/43 and the noise still remain; for testing, I'm using the evaluation board of the L6472;

I haverecorded a video that show the problem I speak; you can find the video at the following link:

http://www.onetimebox.org/box/ugkLeeD3H2kgrrveg

Do you have some suggestion that can help to solve this problem? Best regards ________________ Attachments : mh7123.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HzFH&d=%2Fa%2F0X0000000bIp%2F3YdOH_i_TJr9FQ0xepfMFWwJJ.mzDbiyOtTRfdo41AY&asPdf=falsemh7126.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HzFC&d=%2Fa%2F0X0000000bIo%2F8hWMx2yw6PHTLXKHBxXjEzmifUCz0o8O8uFRVtS5c5k&asPdf=false