2015-07-17 08:04 PM
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-cap2015-07-22 07:47 AM
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 Enrico2015-07-22 07:59 AM
Sorry, I did not read your new post providing more details.
I'll answer you in the new discussion. Enrico