This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS54540 start up

Hi

My 12V to 7.5Vdc @ 150mA to 700mA design from the Web bench simulation simply doesn't seem to start up. The boot pin shows a nice big spike every dozen mSec or so but that output never approaches 7.5V it steps up to maybe 4 V then ramps down to near zero. Never looking like DC either just sawtooth waves.

 

 

Any ideas?