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TPS25947: Circuit breaking during start-up

Jack W
Prodigy 20 points
Part Number: TPS25947

Tool/software:

I am looking for an eFuse that will break the circuit and latch on overcurrent during start-up.

The TPS259474L is the closest I've found, but if start-up current exceeds ILIM it just enters regulation mode instead of breaking the circuit. From the datasheet:

Active current limiting based on RILM is active during start-up for both TPS259470x/2x (Current Limit) and TPS259474x (Circuit-Breaker) variants. In case the start-up current exceeds ILIM, the device regulates the current to the set limit. However, during start-up the current limit is engaged without waiting for the ITIMER delay.

Is there a way to configure the TPS259474L to avoid this? Or another part that does what I am looking for?

One workaround I am considering is disconnecting the load using a MOSFET during start-up, but ideally this wouldn't be needed.

  • 0
    TI__Mastermind 38335 points

    Hi Jack,

    This is consistent will all our eFuses. They go into current limiting mode instead of performing circuit breaker if current exceeds the ILIM during startup. This allows the efuse to still have startup when the current is due to inrush current of cap.

    During current limiting, if the power dissipation is high across the device, then they will go into thermal shutdown and break the circuit which can help in your requirement.

    Best Regards,
    Arush

  • 0 in reply to Arush Gupta
    Prodigy 20 points

    Thank you, Arush.

    We’ve decided to use the existing onboard microcontroller in conjunction with the PG signal to manage current-limited startups. If PG remains low, the microcontroller will disable the eFuse after a defined delay.