C
ChairmanOfTheBored
- Jan 1, 1970
- 0
WTF? I run across them all the time.. *shrug*
Yep. In every package style currently in use for sm signal devices.
WTF? I run across them all the time.. *shrug*
ChairmanOfTheBored said:There are different data sheets for every maker of the 2N2222, and they
ALL differ in one respect or another from the original.
THAT is why the Zetex part IS a 2222 as well.
They (manufacturers) are ALL different,
except for the early original makers of the OEM parts.
After all the other silicon fab houses started making their versions of
it, they all differed on one or more ways. If you can't understand the
concept of how metal conducts heat better than plastic, you need to die
and be reborn in your next life and actually try to learn something in
that one.
You're uneducable in this one.
ChairmanOfTheBored said:Yep. In every package style currently in use for sm signal devices.
How metal conducts is only relevant when a heatsink is fitted. Since
shiny metal radiates heat less effectively than matt black plastic
it's not hard to see how plastic can outperform metal can here. There
is also the lead frame to consider. A plastic device has the die
mounted directly onto a lead frame which then conducts heat away from
the die into the pcb. Metal can devices do not have an equivalent
direct conduction path.
When I pointed out the radiation aspect, John Popelish pointed out that it
is a small part, not significant, and when the Popelfish has translated
things electronical, I tend to listen. You're right about the second part
though, compared to the copper tab formed as a single part with one of the
leads, the thermal conductivity between can and wires is lower. I doubt
it's that much lower though.
When I pointed out the radiation aspect, John Popelish pointed out that it
is a small part, not significant, and when the Popelfish has translated
things electronical, I tend to listen. You're right about the second part
though, compared to the copper tab formed as a single part with one of the
leads, the thermal conductivity between can and wires is lower. I doubt
it's that much lower though.
ChairmanOfTheBored said:The die on the TO-18 is attached to the base of the can... with a
thermally conductive epoxy.
Lostgallifreyan said:When I pointed out the radiation aspect, John Popelish pointed out that it
is a small part, not significant, and when the Popelfish has translated
things electronical, I tend to listen. You're right about the second part
though, compared to the copper tab formed as a single part with one of the
leads, the thermal conductivity between can and wires is lower. I doubt
it's that much lower though.
Western designs? Are we on the road of bashing the US again ?Eeyore said:MooseFET wrote:
Not a problem as I'm using them in a DC regulator circuit. Prety OK for any audio apps
too.
Oops ! Yes, the TIPs are a bit slow. Japanese power devices (notably Toshiba IME) are
typically a LOT faster than 'western' designs btw.
Graham
MooseFET said:It is fairly likely that the leadframe makes more difference than the
metal vs plastic housing. The transistor substrate isn't all them
well connected in either thermally. The plastic part ends up having a
lower junction to case thermal resistance than the metal one. I
suspect that this is due to the heat flowing down the lead frame.
Jamie said:Western designs?
Are we on the road of bashing the US again ?
What the hell does Western have to do with it?
2N2222 Pd = 500mW (metal)
PN2222 Pd = 625 mW (plastic)
US or European.
Slow bipolar power transistors. Don't ask me why but Motorola and RCA never could match
Toshiba or Sanken for device speed combined with good SOA.
Lostgallifreyan said:It's not exactly an order of magnitude, is it? If the thermal resistance
between can and chip were that much greater, I think the Pd difference
would also be greater than that.
I agree. The 2N2222 parts have Kovar or some other iron
alloy leads (gold plated, perhaps) of very low thermal
conductivity, compared to copper,
Solder that lead
to a large area pad on the board, with a short lead length,
and you carry away more heat than all 3 leads of the metal
can might carry.
Plus the thermally conductivity epoxy
carries heat off all the surfaces of the die not bonded to
the collector tab, where the 2N2222 has the die in an
otherwise empty can, so only the collector side has a local
heat sink.
Funny, how the only part that was acceptable in our mil spec designsNo it's not that much but it is the precise reverse of what the resident
FOOL claimed.
Graham
ChairmanOfTheBored said:Funny, how the only part that was acceptable in our mil spec designs
was the metal can variety.
Must have something to do with MTBF.
Whom is laughing at whom now?
MooseFET said:The TIP35 also had a very bad dynamic saturation characteristic. When
the collector voltage got below about 2V, they slowed down to a crawl.
Very likely so and its ability to withstand adverse environments most likely
because of the hermetic packaging. Irrelevant to anything other than military /
aerospace application and the like of course.
I'm laughing at your pathetic attempt to wriggle out of your error by changing
the topic.
ChairmanOfTheBored said:"and the like"? You're an idiot. The metal housed device is better for
more reasons than the hermetically sealed package, idiot.
It has a much broader range of operation.
I am betting that the epoxy package peters out far sooner in designs
where the transistor's capacities are pushed.
You're an idiot. It is still the same topic. It is still a better
part.