59N30 mosfet instead of 50N20?

[Gaber Mohamed Boraey]

Hello everyone

I have 3k UPS with boosting circuit consist of 4 mosfefs of 50N20

And the pwm generator is sg3525

Can these two mosfets be replacement for each other?
Datasheets are attached

 

[sidun.av]

These two look pretty similar to me... What is the exact concern here?

 

[Gaber Mohamed Boraey]

These two look pretty similar to me... What is the exact concern here?

we can replace them to each-other?, the timing differences not a big issue

 

[Gaber Mohamed Boraey]

The rise and fall times are little different, there is one faster than the other turning on and off
This will not affect on switching time between the high and low mosfets?

I would like also if you can explain this issue of adjusting the timing for the mosfets " on and off time " with the pulse duration from the sg3525 ic

 

[danadakk]

The IXSYS has no abs max ratings in its datasheet, the gate charge values different, The Idrain seems lower in ON part.

The SOA curves have enough difference to be possible concern.

You could try them, look at Vgs with a scope for timing/transients, use a IR heat sensor to look at temperature.

Equally contact ON Semi for a recommended replacement......get some advice.


Regards, Dana.

 

[FvM]

You surely should not replace individual transistors in parallel circuit. Different timing of HS and LS switches can but must not necessarily be a problem. If I perform the replacement in a redesign, I'd schedule a complete set of characterizing measurements and possibly adjust circuit parameters. In repair service, it's more trial and error. According to datasheet there's a good chance that it work flawlessly.

 

[D.A.(Tony)Stewart]

Why did they burn out?

Overload on turn on or off?
Inductive load ?
Insufficient cooling?
Marginal rise/falltime affecting Pd?
Are they the PWM lower pair?

At 3kW 230V 50 mohms will dissipate 10W , IF the heatsink is 4'C/W that's a 40'C rise is ok.

 

[Gaber Mohamed Boraey]

The IXSYS has no abs max ratings in its datasheet, the gate charge values different, The Idrain seems lower in ON part.

The SOA curves have enough difference to be possible concern.

You could try them, look at Vgs with a scope for timing/transients, use a IR heat sensor to look at temperature.

Equally contact ON Semi for a recommended replacement......get some advice.


Regards, Dana.

Ok