IRS2092 with gate buffer HELP!!!

[Dzony988]

Hi my friends, long time I posted something on diyaudio!

Finaly I finished my schematic for amp with IRS2092 and bjt gate buffer.
Because in my contry I cant find fets with low gate charge and I cant order form others contry, I think with this schematic and buffer I can drive fets with little large gate charge (80-130nC), IRFB4227, IRFB31N20D, and I want to try IRFP250N because I have 20 pices.

I plan to use low freq. bettwen 250 and 300KHz and on schematic is calulation for all comonets who require different values for different voltages, also components for over current protection and osc.freq.

I use max dead time, 105nS!

I need someone to chack schematic, input part, dead time settings, buffer design and other..
On schematic is not gate diodes 1N5819 after buffer paralell with 10R gate resistors but I will put dem on pcb

Can I go on with this schematic and making PCB?

Thanks a lot and ragards
Nikola

[andrewlebon]

Hi Dzony
greetings PLEASE OMIT 12 volt bias supply use other supply on ucd thread
using 5 pin voltage regulator tip regulator to much heat dissapation
warm regards
andrew lebon

[nigelwright7557]

I would decouple the vcc the oher side of the 4r7 resistor as per datasheet.
You need a 390r resistor between bc639 and pin 5, I found just shorting CSD out blew up the 2092.
I used a 7812 reg plus a couple of 7 watt dropper resistors for the VCC supply.

[nigelwright7557]

Originally Posted by nigelwright7557

You need a 390r resistor between bc639 and pin 5, I found just shorting CSD out blew up the 2092.

The CSD cap is the wrong way around too.

[Dzony988]

i dont understand for csd cap and for 4r7 resistor for vcc. by the way generaly is schematuc good can it work stable as it is? i cant wait to try irfp250n

[nigelwright7557]

You have put decoupling after the 4r7 from vcc, the decoupling should be on the vcc pin.