L6482 FILTER CAP

rengholm · ‎2015-07-17

Posted on July 18, 2015 at 05:04

What is the filter cap required for driving a stepper motor at 5 amps RMS? The schematic from ST shows 220uF 100V but no ESR data. I placed a United Chemi-Con 390uF 100V with an ESR of 28m ohms and a ripple current of 2.6 amps. I now trip the short circuit detect. Any rule of thumb?

#l6482-filter-cap

Enrico Poli · ‎2015-07-22

Posted on July 22, 2015 at 16:47

Hi,

the ESR of the bulk capacitor should be selected according to the current ripple generated by your PWM current control. The value you selected seems ok.

However I don't think the bulk capacitor is the root cause of the OC detection triggering.

Could you please share the following information:

- layout

- MOS part number

- device configuration

Regards

Enrico

Enrico Poli · ‎2015-07-22

Posted on July 22, 2015 at 16:59

Sorry, I did not read your new post providing more details.

I'll answer you in the new discussion.

Enrico