TPS2491 output short circuit

Karthik,

Please refere to the answers in line. Good luck.

-ARtem

1) During short circuit, Gate driver voltage is dipping to Zero, immediately it rises to 4.4V and dips down due to Ct rises to 4V.

   a) What will be output of Power engine in case of short circuit as show in functional block diagram in datasheet.

         * After a short circuit the hotswap will re-start into powre limit. The hotswap will regulate the Vgs to control the current through the hotswap -> this is why your voltage is at 4.4V.  During the power limit the timer will run and once it times out the hotswap will fully shut off.

    b) Which time need to be consider for Gate driver switched OFF whether time between VO to GATE voltage or Gate voltage (4.4V) to Timer ON -->16ms

* The FET will shut off very fast during a short. This prevents large over current. During a re-start into power limit the current is managed.

     c)During short circuit, how GATE driver get the voltage (4.4V)

* see answer to a).

2). When short circuit is removed,

      a)how does Gate driver is ON and switch OFF the Timer? Any control signal from GATE control amplifier switches off the Fault logic circuit. What are the two line connecting to GATE control amplifier.

* If you have a "retry" version of the part (TPS2491) it will attempt to restart with ~1% duty cycle. So if the time is 16ms, it will ~1.6s before trying to re-start the part.

     b) how time requires to switch ON GATE driver?

* see answer above.