Scale able class D 1250W UCD style and Non-UCD style - PCB Ready. Tested.


diysmps Senior Member
Everything was fine until today, irf540z was cold (no heatsink) and worked good on 4ohms load, but now failed. After couple seconds fets become over +70C, sound like underground... Irf540z with 22ohms+ 1n4148 , T106-2 1mm 37turn+ 0,47cap Any suggestion where to search problem?

+- 70vdc is overkill for irf540z, i suggest you use to247 package , and you will be suprise about the sounding and power, try irfp260N with 47 ohm gate, minimum 22uh inductance, there is alot diff between to247 package and to-220 package, reduce fsw 250khz. also you can add totem pole easily to reduce stress on ir2110.