Load current high-side power switch

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I have some motors connected to a battery which I start with a switch. I suppose they have some big capacitors inside their drivers so when I turn on the motors with the switch, they draw a big current (inrush current) and my batteries can not support it, so their voltage drop. As I don’t want that, I decided to add a load switch or high-side power switch. (It could be the ITS4141NHUMA1)

However, I have a question regarding the load current. At normal operation, my motors can draw up to 50 or 60 Amps together.

Will this switch support that load current or will it try to limit it also after start up?

If it will try to limit it too, should I put a relay to short-circuit the switch so my motors can draw enough current during their operation ?

I don’t understand very well what is presented on the datasheet for the current. For Load Current it says self-limited and then in the Protection Functions section it says Initial peak short circuit current limit 1.4A but it does not say anything about steady operation current.

powermotorswitchesinrush-current

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afvmil

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At normal operation, my motors can draw up to 50 or 60 Amps together.

That means that for two motors they could draw 25 amps each and this will still be a problem for that load switch because it has an on resistance of 0.2 Ω. At 25 amps, the power dissipated in the load switch will be 125 watts and the device will fry instantly.

Will this switch support that load current or will it try to limit it also after start up?

It’s wholly unsuited for your application.

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answered yesterday

Andy aka

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• 1Each motor has nominal current of 6.5A and stall current of 12.5A, not 25A. For 6.5A This will make the device dissipate 8.45W and its Ptot is 1.4W so I think it won’t work either, am I right? – afvmil yesterday
• 1@afvmil they will still fry big-time. You need something a whole lot beefier for this. – Andy aka yesterday
• 1I’ve found this reference PROFET® BTS 432 E2 (media.digikey.com/pdf/Data%20Sheets/Infineon%20PDFs/…) I think it can work – afvmil yesterday
• 1@afvmil that looks a lot better but it will still get hot enough to warrant a lot of copper on a circuit board to pull away the heat (1.6 watts). – Andy aka yesterday 

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