High voltage power supply

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In HVPS step-up transformers have large stray capacitance. When transistor turns on capacitive current rushes in and presents big surge immedaitely after that. Than current goes its normal way and value.

It looks like TOPSwitches' built-in current limitation would prevent using them for HVPS.

Is any way to disable or to blank current limitation?

The large spike seen right at the time the MOSFET turns on is actually dependant on a few factors: MOSFET Coss, input voltage and the primary interwinding capacitance.

 

Because of this large spike,  we have a leading edge blanking feature built into the MOSFET current sensing circuitry.  The blanking time varies from device to device, so you'll need to look it up in the datasheet.  

 

Regards,

-The Traveler