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TPS274160: Maximum short circuit current

Chris Johnson
Prodigy 10 points
Part Number: TPS274160

Tool/software:

Hello,

In the data sheet it says 

"For better protection from a hard short-to-GND condition (when the ENx pins are enabled, a short to GND occurs
suddenly), the device implements a fast-trip protection to turn off the related channel before the current-limit
closed loop is set up. The fast-trip response time is less than 1 μs, typically. With this fast response, the device
can achieve better inrush current-suppression performance."

So at some current value it decides that there is a hard short circuit  and initiates the fast-trip protection.

Q1 At what current does the fast-trip protection take over form the current limit function ?

Q2:What is the maximum short circuit current the device can take without damage ?

Reason is that on a hard short circuit test with a 24 V 14 A power supply unit the device failed as shown below

Best Regards,


Chris

  • 0
    TI__Mastermind 29480 points

    Hi Chris,

    Welcome to e2e!

    How did you test the short? For very low resistance and inductance shorts such as VOUT to GND pin shorts, the device can be damaged because the current/temperature increases faster than the device can react. Could you estimate these resistance and inductance parameters?

    Thanks,

    Patrick

  • 0 in reply to Patrick Shalton
    Prodigy 10 points

    HI Patrick,

    Thanks for your response the output was shorted on a test jig, a few cm of track and a DIP switch, so basically 0 ohms and no inductance. The data sheet says the device will protect itself on hard short circuit in 1 us so it shouldn't have any time to heat up. The data sheet does not tell you what fault current it can clear safely. With 0.16 ohm on resistance and 24 V the fault current can be 150 A. The datasheet should give a maximum current that it can tolerate then we could add series resistors in the outputs to protect it.

    Regards,

    Chris