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BOOSTXL-BUCKCONV: Buck converter does not get turned ON



I recently bought BOOSTXL-BUCKCONV eval kit

The kit is not connected to any controller. It's only connected to the power supply which is providing 9V DC on JP1. The LD1 led gets ON momentarily for a sec and then remains OFF. I can see the voltage on the power supply is 9 V but the current increases to a very high value and then settles to 180mA. I expect until I don't connect any controller with a required duty cycle it should not pull any current and the LD1 led should remain ON always.

How can we debug what's going wrong?



  • Vikky,

    Generally speaking, the BoosterPack is only designed to be used in conjunction with a LaunchPad that is actively managing the control signals. There are pull-down resistors installed to seek a safe state, but they can be overcome easily.

    Based on the current draw, I suspect that a component may be damaged.  Does the board still work with TI examples?

    The easiest way to detect damage would be to use a thermal imaging camera to look for a hot spot that does not exist on a good board.  Otherwise, manual probing will be required at the major test points and component pins to find the energy leakage path.  If probing does not turn up any clues, the next step would be to exhaustively depopulate components until the fault is found through elimination.

    I would recommend experimenting with the 3.3V supply for U2 when 9V0 is powered up to see if stray voltage on U2-3 and U2-4 might be internally shunting to its supply rails in a damaging fashion.  It may also be a good idea to clamp the 9V0 current to something moderately greater than a good board in order to reduce further damage.