DRV8434S: Bulk capacitance value

Hello team,

I want to decide the bulk capacitor value for this device, but there is no equation for required capacitance.

I have watched the video: Voltage margin and bulk capacitance and found an equation below.

I believe the I from the equation is peak current, not stall current correct?
If so, I think DRV8434S regurates the current by ITRIP level which is decided by the device. So this kind of startup inrush current is not present for DRV8434S?

How can I choose the value for ΔV? Is it decided by the recommended input voltage level of the stepping motor in the system?

Best Regards,
Kei Kuwahara