MOSFET burning with In-System programming

Good day everyone!

Apologies if this might have asked before in this forum but I couldn't find any matching threads, thus posting.

I've this circuit board with an In-System programming header for the ease of program updating. The circuit works fine if I insert the Atmega to the board after uploading the program.

But since its driving a push-pull transformer through a set of MOSFETs, whenever I try to burn the program through the ISP header, both FETs get turned on at the moment of uploading and as you expect, SMOKES! :fearful: from FETs.

Is there any particular circuit setup so that the high and low side MOSFET gates are not simultaneously affected by the GPIOs at the time of programming ?


I can only suggest not putting FETs on D11-12-13 without some kind of buffer that would be turned off during programming, but I guess too late for that now.

Continue to program offboard would seem the best choice.

Or, install a bootloader, and load code via Serial (D0, D1) instead of ISP.