CEB703 replacement

[Smiffy]

Hi All
I had a nice accident with a naff old ECS board.I overclocked a tualatin 1.3Ghz to 1.73Ghz but i think the current strain was to much for the regs and a CEB703(30v 40A) let go in a puff of smoke.As the cpu amazingly still works can I upgrade the CEB703s on my other two boards to something beefier,say FDB7030L.(30v 100A)
Thanks for any info
Smiffy

[Rainbow]

Re: CEB703 replacement

I've replaced burnt mosfets on many boards - sometimes with better replacements. Not only the current rating but also Rds(on) matters - the smaller Rds(on), the cooler will the mosfet run.

[Smiffy]

Re: CEB703 replacement

Hi Rainbow
Ta for advice
RDs(on) on for the 703AL is 17 milli ohms at Vgs=10v and 30 milli ohms at Vgs 4.5v
On the 7030 it is 7 milli ohm at Vgs 10v and 10 milli ohm at Vgs 5v
Smiffy

[Rainbow]

Re: CEB703 replacement

If both are logic-level mosfets, then it should work fine.
Once I used non-logic level mosfet as an replacement. It worked the board had power-up problems with some CPUs. So I replaced them with logic-level ones later and it worked fine then.

[Smiffy]

Re: CEB703 replacement

Hi Rainbow
Yes it is Logic level.Having trouble sourcing it though so may have to look at something else.
Smiffy

[MD Willington]

Re: CEB703 replacement

I take it you've also checked the caps? If you're going to dig into it, best to do the whole show.

Cheers.

[Smiffy]

Re: CEB703 replacement

Hi
HAve checked them all,no pops or bulges but have enough Panasonic FCs and Rubycon ZLs lying around to change them all anyway.Hoping STB80NF03L mosfets woould be ok.80 Amp with Rds(on)0.004 ohms but dont know if its logic level compatible.Smiffy

[PeteS in CA]

Re: CEB703 replacement

STMicroelectronics' datasheet calls it a "Low threshold drive" part.

[Smiffy]

Re: CEB703 replacement

Hiya PeteS
That should be ok then.Will heatsink them up.I can only conclude the originals cop it because the processor wants more amps that they can supply.
Smiffy