TPS2491: Solenoid output

Michael Fontanarosa

Part Number: TPS2491

Not having all of the required information as yet, I have an application where I need to switch 32V max into either one or two solenoids in parallel. I do not know the inductance value (working on that), but I've been told that the nominal resistance would be 18.5 Ohms which translates to 1.75 Amps. The worse case current is supposed to be less than 2 Amps per solenoid. However, the customer believes that the inrush current will be somewhere between 8 to 10 Amps per solenoid. Like the inductance, I am trying to find out the duration of that inrush.

Would the TPS2491 be a good fit for this application? If so, would excel spreadsheet be useful to use?

over 5 years ago

0 Rakesh over 5 years ago

TI__Guru** 105361 points

Hi Michael,

We have other devices from Smart High Side Switches family which are more suitable for your application. My colleague will help you on the right part recommendation.

Meanwhile, you can go through the below collateral for more details.

https://www.ti.com/lit/an/slvae30a/slvae30a.pdf

https://training.ti.com/sites/default/files/system-level-design-considerations-for-driving-and-diagnosing-inductive-load.pdf

Best Regards, Rakesh

0 Shreyas Dmello over 5 years ago in reply to Rakesh

TI__Mastermind 32650 points

Hi Michael,

I believe that the high activation inrush current might be too much for our High Side Switches to handle at 32V.

I think you may need a dedicated solenoid driver. You can find TI solenoid drivers here: https://www.ti.com/motor-drivers/solenoid/overview.html

Unfortunately, I am not familiar with the product line but if you have a question on these devices feel free to ask an E2E question about one of these devices and the responsible engineer will be assigned to it.

0 Michael Fontanarosa over 5 years ago in reply to Shreyas Dmello

Prodigy 30 points

Hi Shreyas -

The high side switches that you mentioned as not being a good candidate all have the pass element MOSFET built into the IC, which would be the reason why the current is too high. The TPS2491 part that I am interested in using has an external MOSFET pass element, so the current handling shouldn't be an issue. I was more wondering how to deal with the high inrush against setting a reasonable over current point such that I don't have the inrush current trip that.

Any suggestions?

Thanks,

Michael

0 Shreyas Dmello over 5 years ago in reply to Michael Fontanarosa

TI__Mastermind 32650 points

Micheal,

Both our eFuse offerings and HSS offerings at this time cannot change their current limit dynamically during operation.

The high inrush current is too high for the integrated HSS and I believe the eFuse devices are not meant to drive inductive offboard loads.

As a result, I would highly recommend a dedicated solenoid driver especially since you are using an external FET.

0 Michael Fontanarosa over 5 years ago in reply to Shreyas Dmello

Prodigy 30 points

Hi Shreyas -

Thanks again for the response. The solenoid driver products that I find on the TI website are for the most part low side drivers and some H-bridge types. Unfortunately, I only have access to do a high side drive on the solenoid load.

I'll probably do something different, so thanks for your help.

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TPS2491: Solenoid output