Power Transistors Recommendations

Thread Starter

Wendy

Joined Mar 24, 2008
23,483
@MrChips
So I was going through the Project Parts Reference V2.0 looking for some regular power transistors and realize the only ones that are in there are darlingtons. So I'm now going to ask for recommendations I don't really like the old 2N3055 transistor because of its low gain I would like to have someone that something that has a average beta of 40 or so. I also am a fan of the TO220 case style, I would like both NPN and PNP complimentary if possible.
 

Ian0

Joined Aug 7, 2020
10,277
Have a look at those offered by Diodes. (www.diodes.com). Diodes used to be Zetex, who used to be Ferranti, who introduced the ZTX range way back, which always had better hfe than average. There's a lot of surface mount, but still a good selection of TO220.
Another range of modern devices is the Nexperia PBSS range.
Of course, the mainstay of audio power amplifiers used to be Motorola transistors, which are now OnSemi.
 

Irving

Joined Jan 30, 2016
4,077
Have a look at those offered by Diodes. (www.diodes.com). Diodes used to be Zetex, who used to be Ferranti, who introduced the ZTX range way back, which always had better hfe than average. There's a lot of surface mount, but still a good selection of TO220.
Another range of modern devices is the Nexperia PBSS range.
Of course, the mainstay of audio power amplifiers used to be Motorola transistors, which are now OnSemi.
Diodes master list seems to list only SMD parts now, Mouser and Digikey for that supplier list a few TO220 but all showing as obsolete & zero stock.

OnSemi 2SC6144SG (NPN) & 2SC2222SG (PNP) are good all-round power BJT in TO220 case, good for 50v & 10A and price-comparable ($0.85) with TIP41C/TIP42C with slightly better specs
 

Ian0

Joined Aug 7, 2020
10,277
Diodes master list seems to list only SMD parts now, Mouser and Digikey for that supplier list a few TO220 but all showing as obsolete & zero stock.
You're more up to date than I am! I did buy some Diodes TO220 devices recently, but they were MOSFETs.
Are there any applications still remaining apart from Class-A and AB audio amplifiers that require a bipolar transistor to dissipate significant amounts of power?
 

Thread Starter

Wendy

Joined Mar 24, 2008
23,483
Not really, just me playing. The problem for MOS FETs is a tend to work better with an on off situation and from what I can tell are not very linear. Bipolar still rules the roost as far as low voltage linear components as far as I am concerned.
 

Ian0

Joined Aug 7, 2020
10,277
Not really, just me playing. The problem for MOS FETs is a tend to work better with an on off situation and from what I can tell are not very linear. Bipolar still rules the roost as far as low voltage linear components as far as I am concerned.
Big MOSFETs need a lot of current to charge the gate capacitance if you want any speed out of them. Bipolars need gate current whilst ever they are switched on. Bipolars are really slow to turn off, especially if they have been driven into saturation.
It's a trade off on linear applications. Bipolars are more linear, have more Gfs but they are slower. You can put more feedback around a MOSFET amplifier and the overall result is much the same.
 

Irving

Joined Jan 30, 2016
4,077
You're more up to date than I am! I did buy some Diodes TO220 devices recently, but they were MOSFETs.
Are there any applications still remaining apart from Class-A and AB audio amplifiers that require a bipolar transistor to dissipate significant amounts of power?
BJT still easier to use for linear regulator, or extension to LM317/337


The problem for MOS FETs is a tend to work better with an on off situation and from what I can tell are not very linear.
MOSFETs intended for purely linear operation do exist, eg for e-loads in battery /PSU testing, mostly IXYS and ST parts, can handle 500W+ but expensive at $20 - 30+ each
 

Ian0

Joined Aug 7, 2020
10,277
BJT still easier to use for linear regulator, or extension to LM317/337
But who does that when there are ICs such as LMR38020?
MOSFETs intended for purely linear operation do exist, eg for e-loads in battery /PSU testing, mostly IXYS and ST parts, can handle 500W+ but expensive at $20 - 30+ each
If you want linear MOSFET, all you need is an old MOSFET.
The occurrence of secondary breakdown depends on the position of the zero temperature coefficient point. It's much lower in older MOSFETs. Whilst the lateral 2SK134 copies have rather too high Rds(on), you can still get IRF130, IRF140, IRFP240 etc. which are pretty much immune from secondary breakdown, and can be successfully used in linear applications.
I've made lots of audio amplifiers with IRFP240/IRFP9240 as the output stage and the devices are still relatively cheap. They don't handle 500W+ but can be paralleled.
RIP 2SJ115/2SK405!
 

Thread Starter

Wendy

Joined Mar 24, 2008
23,483
And the winners are MJE 3055, and MJE 2955. I will be adding these to the parts list as soon as I finish this post
 

Ian0

Joined Aug 7, 2020
10,277
And the winners are MJE 3055, and MJE 2955. I will be adding these to the parts list as soon as I finish this post
And an MJE3055 is a 2N3055 in a plastic package which you "don't really like the old 2N3055 transistor because of its low gain", and you are a "fan of the TO220 case style" and these are TO218??
 
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