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TPS25982: Current Limiting

Part Number: TPS25982

Hello,

For some context, I'm currently working on integrating this chip into an application for the purpose of limiting the current into a motor. We have a battery that can only supply 30 amps or so of current, and in 99% of our use cases, we never go above that amount, usually below 10 Amps. In extremely rare cases however, the motor we are using seems to be stalling and drawing more than 30 amps, which enables an overvoltage circuit on the battery that shuts it down. We would like to avoid even reaching that state, so we want to implement this chip that limits the current at its max (15 Amps). Changing the motor/battery is the eventual goal, but for the short term it is not a possibility.

I'm trying to understand conceptually and practically how exactly this chip works in terms of active current limiting, so I apologize if this comes off as simple or straightforward. When the chip detects the load asking for more current, I see that it only allows pulses through which effectively limit the current. What I'm confused by is what comes after. I read that the chip will limit the voltage, which effectively limits the current, but it will eventually shut down. Is this the right understanding? I would like to avoid the chip fully shutting down so I'm a little cautious of that behavior. 

Any guidance or direction on my logic/understanding would be great.

Cheers!

  • Hi Joshi,

    Welcome to E2E!

    In current limiting mode, eFuse devices limits current into the load by dropping voltage across the eFuse device. This situation causes power dissipation of (VIN-VOUT)*ILIM across the eFuse and raises the junction temperature which eventually shuts down the eFuse when the junction temperature hits Thermal Shutdown Threshold (150C).

    So there is a limit on amount of time eFuse can serve the load in current limit mode. Below plot gives the information.

    Best Regards,

    Rakesh