General purpose NPN / PNP transistors >= 500mA

[roxlu]

Hi there,

I'm looking for general purpose NPN/PNP transistors
with a max current around the 500mA. I've found the
bc547, but I'm also looking for PNP and other
relevant transistors I could use.

Greetings Roxlu

 

[Pooh Bear]

Hi there,

I'm looking for general purpose NPN/PNP transistors
with a max current around the 500mA. I've found the
bc547, but I'm also looking for PNP and other
relevant transistors I could use.

The BC547's complement is the BC557.

2N4401 and 2N4403 are complementary 40V 600mA switching transistors ( low Vce
sat ) in TO-92 too.

Graham

 

[John Fields]

Hi there,

I'm looking for general purpose NPN/PNP transistors
with a max current around the 500mA. I've found the
bc547, but I'm also looking for PNP and other
relevant transistors I could use.

 

[Winfield Hill]

Pooh Bear wrote...

The BC547's complement is the BC557.

2N4401 and 2N4403 are complementary 40V 600mA switching
transistors ( low Vce sat ) in TO-92 too.

Graham's suggestion is good, roxlu, those two parts are
true jellybeans. But for 500mA and up, while still in
the convenient TO-92 package size, I suggest you choose
parts from the Zetex E-line. DigiKey is a good source.
http://www.zetex.com/3.0/transistor_search.asp

 

[roxlu]

I also found the
bc337 NPN (max 800mA)
bc327 PNP (also max 800mA)

I want to use them for multiplexing LEDs with around the 32 rows and 16
columns,
will those do for that when I limit the current for the columns so that
it will be max
800 mA).

Gr. Roxlu

John Fields schreef:

 

[Joerg]

roxlu wrote:

I also found the
bc337 NPN (max 800mA)
bc327 PNP (also max 800mA)

I want to use them for multiplexing LEDs with around the 32 rows and 16
columns,
will those do for that when I limit the current for the columns so that
it will be max
800 mA).

If that's continuous duty they will become quite hot. Vce sat can be
more than half a volt at 800mA. Operating something at the absolute
maximum ratings is something I don't do in a design.

Also, don't expect a lot of current gain at those load levels. Can't you
use FETs?

 

[John Larkin]

Hi there,

I'm looking for general purpose NPN/PNP transistors
with a max current around the 500mA. I've found the
bc547, but I'm also looking for PNP and other
relevant transistors I could use.

Greetings Roxlu

I like BCX70/71 as standard gumdrops, for their fantastic betas, but
they're only rated for 200 mA.

John

 

[John Fields]

I also found the
bc337 NPN (max 800mA)
bc327 PNP (also max 800mA)

I want to use them for multiplexing LEDs with around the 32 rows and 16
columns,
will those do for that when I limit the current for the columns so that
it will be max
800 mA).

---
Please bottom post.

Since you'll be multiplexing 16:1, the average current, per column,
if all 32 row LEDS are lit at once, will be 800mA/16 = 50mA which
should be fine.

 

[Walter Harley]

Hi there,

I'm looking for general purpose NPN/PNP transistors
with a max current around the 500mA. I've found the
bc547, but I'm also looking for PNP and other
relevant transistors I could use.

I've been having good luck with BD135/BD136, suggested by others here a year
or two ago. In my application I only push about 200mA through them at most,
but they're rated to 1.5A and the TO126 case will dissipate somewhat more
heat than a TO92 would, while still being smaller than a TO220. They come
in various beta selections.

 

[Pooh Bear]

I've been having good luck with BD135/BD136, suggested by others here a year
or two ago. In my application I only push about 200mA through them at most,
but they're rated to 1.5A and the TO126 case will dissipate somewhat more
heat than a TO92 would, while still being smaller than a TO220. They come
in various beta selections.

It's a shame there's not more stuff in that package size.

Graham

 

[Winfield Hill]

Pooh Bear wrote...

It's a shame there's not more stuff in that package size.

Indeed, but the BD135 and BD136 aren't very impressive when
used as switches above 200 to 400mA. That's because they're
total wimps for beta above 400 to 500mA, under 75 typical,
and only 25 worst case, even for the high-beta version. And
their collector-saturation voltage rapidly rises above 500mA,
where it's already up to 500mV. Diederick says he wants to
switch 800mA, where the worst-case limit is 810mV at 25C,
rising to perhaps 1000mV at higher temps. And that's with a
very painful rather-high 80mA drive!

By comparison a part like the Zetex ZTX849, for example, will
run nice and cool, thanks to its beta of 100 min, 200 typical
and its low 50mV saturation voltage at 1000mA, which is with,
note!, only 20mA base drive! An amazing part like that can
give a small MOSFET a real run for its money! In fact, Zetex'
entire Super E-line TO-92 series is amazing.

BTW, the FZT849 and ZXT849 are pretty cool parts as well, more
SMTs helping to give the old TO126 case a permanent heave-ho.
The ZTX649 is a little less expensive.

 

[John Popelish]

Walter Harley wrote:


It's a shame there's not more stuff in that package size.

I have had more bond failures with the TO126 case than with all other
cases combined. The combination of stiff lead frame and minimal epoxy
to contain them is very poor, in my opinion.

 

[Joerg]

Hello Win,

Indeed, but the BD135 and BD136 aren't very impressive when
used as switches above 200 to 400mA. That's because they're
total wimps for beta above 400 to 500mA, under 75 typical,
and only 25 worst case, even for the high-beta version. And
their collector-saturation voltage rapidly rises above 500mA,
where it's already up to 500mV. Diederick says he wants to
switch 800mA, where the worst-case limit is 810mV at 25C,
rising to perhaps 1000mV at higher temps. And that's with a
very painful rather-high 80mA drive!

Ouch. This application really calls for FETs if he has enough gate drive
voltage.

 

[roxlu]

Hi all,

I've bought the bc337 NPN (max 800mA) and bc327 PNP (also max 800mA),
which
work great for now! I'll keep you informed when I change transistors.

Greetings