Need a tough TO-220 Bipolar...

[EchoWars]

What I''m looking for is a complementary pair of TO-220 devices capable of operating as output transistors for a small (35WPC) amplifier. I have, in the past, used the On-Semi MJE15032G & 33G for this purpose, but I'd really like to find something with a full plastic case that needs no insulation from the heatsink.

Bottom line specs might be something like:
120Vceo or better
Ic = 5A or more
Pc = 50W or more (if possible)
Ft = 20Mhz

Anything out there? Or is the plastic case going to be the limiting factor for power dissipation?

[ingenieus]

TO-220 power devices all have metal tabs. If you are not squeezed for space, how about something bigger?

If you go for a TO-264 device, the world is your oyster. They are about double in width and height (which makes them four times the size). And probably overkill for what you want to achieve. Probably more expensive as well.

A good answer to your question seems to be the 2SC5198/2SA1941. They meet all of your specs and are closer in size to the TO-220. They also have metal tabs, but it does not seem to be in contact with the back plane. I've never seen one - just going on what is in the pictures. Perhaps somebody who have used them can confirm this.

[EWorkshop1708]

2N6488/6491 Onsemi has datasheet

80v 15A 75W

I have a car amp that has 2 pairs of these per channel.

[ingenieus]

I've looked the 2N6488/2N6491 over. They seem like quite sturdy little suckers. Very nicely priced as well. I'm currently working on a design for a low budget guitar amp. These seem to fit the bill. I was thinking about using the hoary old TIP3055/TIP2955 but these are in a different class.

Their fT is 'only' 5MHz. EchoWars would have to consider this in making his choice. And they have the TO220 affliction - that metal tab that needs a washer.

[wahab]

BD911/912 15A 100V 90W.
Darlingtons BDW93C/94C 12A 100V 80W.

A 30W amplifier seems the absolute limit for such devices.

Using Sanken s darlingtons would be a very good option to make
a low component count design , not counting the exceptionnal perfs
of this brand s devices.

Darlington Sanken : MP1620/MN2488 10A 150V 150W FT= 50/55mhz.

[AndrewT]

Clamp them with an insulating strip between them and sink.

[wg_ski]

Originally Posted by EchoWars

Anything out there? Or is the plastic case going to be the limiting factor for power dissipation?

The full plastic case will be a major thermal problem. There are several TO-220 pairs out there that are available in both normal TO-220 and overmolded - and they go from 50+ watts down to 20 in that package.

I think Fairchild is making versions of the C5200-equivalent die packaged in the (normal) TO-220. It doesn't have the SOA because it's too small to get the heat out of - but they're better than TIP devices. IME, dissipating more than 40W with *any* TO-220 and practical heatsink is impossible.

[EchoWars]

Thanks for the suggestions...digging through many more data sheets (and getting crosseyed in the process), I see that my suspicions were correct, and wg_ski is on the money...the plastic case is a big limiting factor for power dissipation.

ingenieus, the large pic you show I have always referred to as the TO-3P(N) which is about 16mm wide. The TO-264 is about 20mm wide, and won't fit. BUT, the 16mm TO-3P(N) should just squeeze in there.

As far as 30W being the limit for a TO-220, I have a little Pioneer SA-510 (rated 33WPC, measures about 43WPC) that smoked its original 'batwing' outputs years ago, and I stuck in some of the On-Semi MJE13032 & 33 TO-220 transistors. It has been fairly abused since, driving all kinds of funky loads, but I've yet to find a way to blow those devices.

[woody]

You may want to look at using insulators with low thermal resistance. With that
small contact area the insulator's thermal resistance is a big issue.

[spind]

I'm not positive, but it looks like the Fairchild FJPF5200 and its complement are in a full plastic case (TO220F package). They are rated for 50W whereas the metal backed FJP5200(TO220 package) is rated at 80W. Both are available at Digikey.

Good luck.

Steve.