TOP255PN
Drain voltage not switching even when control voltage above 5.8V, what could be the reason?
Comments
I've applied 15V to Vds through 250 ohm resistor and applied 5.8V to control pin, i dont see any switching, im new to this, need help.
Normally 4M resistor is used for 85Vac-265Vac applications. So you have to adjust the resistor based on your input.
I even tried applying 110VAC input with 4M resistor for line sensing and applied about 6.15 V for control pin, still no switching at Vds, i also added 47uf cap at control pin for instantaneous gate drive.. wat could be the reason for no switching..
Hpefully schematic an tell us something.
topswitch enters into auto-restart mode after few seconds at 50% load and there is no voltage across 5V output, dont no whats wrong? need help
PLS check the Vds to make sure no auto restart. And PLS check the line sense resistor. If possible, PLS upload a schematic. And schematic can help a lot.