Mp3910 hard problem

step up dcdc 7.5V to 12.8V and 2.5A load can’t output load more 1A

topology.

I sure problem in GND way.

angDeepinScreenshot_выберите-область_20210811094623

is new topology good?

Hi Gravl4,
What happens when the circuit is loaded past 1A? Have you tried changes to the circuit? You can look at the gate drive to the FET and check for normal operation up to where it doesn’t work anymore, and that the gate(s) are being driven correctly not overloading the driver. Also monitor the sense resistor voltage to check that switch current is not too high. For the layout, the input and output caps need short connections to ground, common with the sense resistor ground connection.