L6470

[eyals111]

Posted on June 03, 2012 at 21:47

hi ,

i am currently evaluate l6470 and have a few questions :

1. does the driver suitable for stepper motor with max 3A current per phase ?

2. how to obtain maximum holding torque ? ( setting K_HOLD to FFh ?)

#go_until-error #l6470

[Enrico Poli]

Posted on June 06, 2012 at 15:34

Hello,

The L6470 maximum current rating is 3Arms, so it is theoretically possible to drive a 3A stepper motor in continuous mode (no stop operation). However the power dissipation limit is stricter than the maximum current one. So the L6470 can drive a 3A load only for a short time.

This time depends on the thermal characteristics of the package and of the application (board layout, heatsinks, etc.).

The maximum holding torque is obtained with the maximum phase current, but usually a lower torque should be enough to keep the motor position, otherwise the motor could be under-sized.

The L6470 uses a voltage mode control algorithm, so a FF value in KVAL_HOLD parameter implies that the maximum

voltage

 (VS) is applied to the motor phase. This voltage generates a phase current according to the motor phase resistance Iph = VS/Rph. Normally this current is much greater than the motor current rating (and maybe of the overcurrent protection threshold also).

Kind Regards

Enrico

[edgar23]

Posted on November 19, 2012 at 10:02

Hi..  

I´ve been working with the L6470 Chip..https://www.sparkfun.com/products/10859so I have a couple of questions..so hope that you could help me..

 First all worked preatty good.I was able to running with very good  Torque and  with velocity values( 6000 steps/sec). with these motor.. 

http://www.phidgets.com/products.php?category=23&product_id=3317_1

Power Supply: 12V 4 amps

 I changed my Power Supply to 12V and 15 amps.. because I need to drive 7 motors at the same time..

I've tried so far 5 chips and they can not to drive the motor beyond 1000 steps / sec

Apparently (i suppose) they have not enough torque and stops when the maximum speed is for example 1200... 

 i suppose that i need to change the values form KVAL_HOLD, KVAL_RUN, KVAL_ACC and KVAL_DEC registers but actually I tested all posible values/configuration without succes...

What Im doing wrong...?

Anybody have a similar issue..?

Thanks

[Enrico Poli]

Posted on December 04, 2012 at 16:20

Hello,

It could be a resonance issue. Try to add a small load on the motor shaft.

Regards

Enrico

[edgar23]

Posted on March 06, 2013 at 12:09

Hi 

If the switch is closed the motor stops just for a moment and turns again although the switch is permantly close..dont performs HARD_STOP.

I think my register configuration is correct.. acctually Im be able to run many of the the L6470 functions succesfully  except GO_UNTIL_ ERROR

have you any idea how can i debugging this problem..?

Thanks..

[lei]

Posted on June 30, 2014 at 15:02

Hi,

I am doing the evaluations by its demo board.

But I found The duty cycle could not get to max. Even if KVAL_RUN is set to max, the duty cycle seems to be regulated from 50% to 100%. So the torque is always not high enough compared to other motor drivers. And other settings I should try?

Thx