Hello,
I am using the TPS54336EVM-556 to operate a bilge pump (SFBP1-G350-1; 12V bilge pump). I replaced R8 with a 10K resistor to modify the output to ~8.8 V. At this voltage, the pump draws about 400 mA.
This board does a great job powering the pump at first, but when the voltage of the battery pack drops below ~14 V, then it runs into problems. It seems to not be able to provide enough current to the pump, and the output voltage drops to ~3-4 V. If i disconnect the pump, then Vout returns to 8.8V.
I noticed that the minimum Vin for the eval board is 8V for a 5V Vout, suggesting that Vint must be significantly higher than Vout. However, i cannot find any information on this in the data sheet for the board or the IC.
Why does this board have trouble supplying the necessary current? and is this fixable by replacing some R/C on the board?
Thank you very much!
Yui
