2012년 7월 12일 목요일

[TI] TPS54226/TPS54326 latching after short circuit

Design Notes

Q: TPS54326 Won't recover after shut down by 12244

I'm using a TPS54226/326 in a design.  When I briefly short the output to ground the converter does properly shut off but when I remove the short it does not turn back on but instead remains shut down.  According to the data sheet this should not happen.  The input supply is steady through the entire short and remove short event.  Besides that everything else seems to work perfect.

A: Re: TPS54326 Won't recover after shut down by 1559531

The Current Protection paragraph on the data sheet is a little misleading. If a short triggers the UVP for greater than 250us the circuit will latch off.

OCP its self is non latching.  if the overload is such that the output voltage falls less than 30 % it will recover automatically when the overload is removed.

UVP is latching.  If the over current condition causes the output to fall more than 30%, then the UVP latching protection is activated.


출처: http://e2e.ti.com/support/power_management/non-isolated_dcdc/w/design_notes/1663.aspx

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