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TPS650832 emergency shutdown

Antony Lin
Genius 13480 points

Hi,

For testing purpose, customer would like to create emergency shutdown on purpose from events as below.

  1. Powergood Fault
  2. Tj > Tcritical

Can you suggest some easy way to create such scenario without damaging the chip?

Thanks!

Antony

 

  • 0
    TI__Mastermind 31655 points
    Hi Antony,

    1. To induce a powergood fault in a safe manner, the customer can change the current limit for one of the voltage regulators. This is done by changing an external resistor as explained in Section 7.2.2.1.5 of the datasheet. Note that this cannot be done on VR2, since it has a fixed internal current limit. The customer can decrease the current limit to its minimum, and use an active load to attempt to draw more than the current limit. Once the voltage droops below 90% of Vout, a powergood fault will trigger emergency shutdown.


    2. What is the customer's Tcritical set at?

    Thanks,
  • 0 in reply to Scott Cummins
    TI__Genius 13480 points

    Hi,

    Tcritical should be the default value.  Can we configure Tcritical in our chip?

    Thanks!

    Antony

  • 0 in reply to Antony Lin
    TI__Mastermind 31655 points

    Hi Antony,

    Tcritical is an OTP value. If the Tcritical is too close to the maximum operating temperature, then it will be difficult to safely trigger the emergency shutdown in this way. The customer will need to use a thermalstream or a temperature chamber to increase the temperature of the device. Putting a heavy load on the outputs will also increase the junction temperature, but it can be more difficult to control the way it affects the actual junction temperature.

    Thanks,