I want to replace my old motherboard (Socket 5 - 478), CPU socket converter MOSFETs and power BJTs. e.g. D45H2A, FDB6030L
They haven't failed yet, but the goal is to avoid potential failures in the near future and reduce heat generation.
1. Which parameters in the datasheet are important for determining whether a product is equivalent?
2. Are there parameters that indicate better performance?
What model of motherboard ? Are you a 'overclocker'? Some times the thermal stress induced to the pcb while replacing them is not worth it (they are not like caps). I recommend doing that only if your VRM stage is weak/poorly designed.
Parameters to look at: not a comprehensive list but a good starting point.
Ic collector current (for BJT), Id (drain current) for MOSFETS. The higher the better, at least equal to the original parts.
Vgth (threshold gate voltage) for MOSFETS, Vbe for BJT. The closer to the original parts, the better
Thermal resistances: junction-case, junction-ambient. The lower the better (degrees per watt)
Max dissipated power. At least equal to the original parts.
I'm sure I'm missing a few
(hfe21=transfer coefficient for BJTs and gm=gain for MOSFETS are not that important in a switching application, but they would be important in a linear regulator setup, which you aren't likely to find on motherboards from the past 30 years or so)
I/O, I/O,
It's off to disk I go,
With a bit and a byte
And a read and a write,
I/O, I/O
rds. Resistance when on, lower the better, less losses.
Cheers,
Great Northern aka Canada.
pentiumspeed wrote on 2023-03-23, 22:40:rds. Resistance when on, lower the better, less losses.
Cheers,
yes, for MOSFETs. For BJT the parameter would be VCEsat (saturation voltage collector-emitter, the lower the better)
I/O, I/O,
It's off to disk I go,
With a bit and a byte
And a read and a write,
I/O, I/O
For MOSFETs first thing , mind the channel type n or p. When searching for equivalents, i find it easy to use something like 'n mosfet X volts Y amps ' , where X is Vdss and Y is Id , the rest (Id pulse , pch ..) you can compare it in the datasheet. Same for BJTs , mind NPN , PNP , Darlington then X volts Y amps , X is Vceo and Y is Ic the rest in the datasheet. But again what is your motherboard ? (Socket 5 - 478) sounds to me like a range of sockets and many socket 5 MB's have LDOs .