Why buy ZTX649B when another is better and cheaper?

[Watson A.Name \"Watt Sun]

Why does Mouser charge $50 a hundred for the ZTX649B when I can get the
Panasonic 2SD965, handles more current than the ZTX, and costs nearly
half the price, $27 a hundred fron BDent.com. Seems like everyone
recommends buying the Zetex stuff, but I don't see them used in
commercial equipt. Probably because they're more expensive.

 

[Tim Shoppa]

"Watson A.Name \"Watt Sun - the Dark Remover\"" <NOSPAM@dslextreme.com> wrote in message news:<boenm2$4opqs$1@hades.csu.net>...

Why does Mouser charge $50 a hundred for the ZTX649B when I can get the
Panasonic 2SD965, handles more current than the ZTX, and costs nearly
half the price, $27 a hundred fron BDent.com. Seems like everyone
recommends buying the Zetex stuff, but I don't see them used in
commercial equipt. Probably because they're more expensive.

The Zetex part has way lower Vce at saturation (both "typical" and
"guaranteed".) Whether that's relevant to you or not, I don't know.
But for motor drivers etc. the Zetex parts are well-known, even though
the Unisonic/Panasonic/no-name parts probably outsell them.

Zetex is certainly a little odd in their marketing approach. Witness
their recent push into LNA's and MMIC parts, which seems to be driven
much more by press releases than any actual technology advances. Maybe
they win on price, but that's the least important parameter to me for these
parts.

Tim.

 

[Watson A.Name \"Watt Sun]

Tim Shoppa wrote:

"Watson A.Name \"Watt Sun - the Dark Remover\"" <NOSPAM@dslextreme.com> wrote in message news:<boenm2$4opqs$1@hades.csu.net>...

Why does Mouser charge $50 a hundred for the ZTX649B when I can get the
Panasonic 2SD965, handles more current than the ZTX, and costs nearly
half the price, $27 a hundred fron BDent.com. Seems like everyone
recommends buying the Zetex stuff, but I don't see them used in
commercial equipt. Probably because they're more expensive.

The Zetex part has way lower Vce at saturation (both "typical" and
"guaranteed".) Whether that's relevant to you or not, I don't know.

Have you checked the specs for the 2SD965? It'll handle 5 amps.
Presumably at 3A (the max that the Zetex will handle), it'll have lower
Vce(sat). Yeah, it's relevant, the main reason to use these transistors.

But for motor drivers etc. the Zetex parts are well-known, even though
the Unisonic/Panasonic/no-name parts probably outsell them.

Zetex is certainly a little odd in their marketing approach. Witness
their recent push into LNA's and MMIC parts, which seems to be driven
much more by press releases than any actual technology advances. Maybe
they win on price, but that's the least important parameter to me for these
parts.

You don't mind paying $50 instead of $27?

> Tim.

 

[Tim Shoppa]

"Watson A.Name \"Watt Sun - the Dark Remover\"" <NOSPAM@dslextreme.com> wrote in message news:<bogfcu$4p3bu$1@hades.csu.net>...

The Zetex part has way lower Vce at saturation (both "typical" and
"guaranteed".) Whether that's relevant to you or not, I don't know.

Have you checked the specs for the 2SD965? It'll handle 5 amps.
Presumably at 3A (the max that the Zetex will handle), it'll have lower
Vce(sat). Yeah, it's relevant, the main reason to use these transistors.

Yes, I looked at the two curves and specs. The Zetex has much lower
Vce(sat) than the 2SD965 at both 3 and 5 Amps:

2SD965 ZTX649

1A .4V typ .1V typ
.3V guaranteed

3A .6V typ
1.V guaranteed .35V typ

5A 1.2V typ .55V typ

Remember that even though the 2SD965 is rated at 5 Amps, with a 1.2V Vce(sat)
at 5 Amps it'll be dissipating 6 Watts, which is six times its avg power
rating. Again, whether this is relevant or not to you will depend on
your duty cycle.

In short: don't look at Ic(max), look at your collector current and
the Vce(sat) at that current, multiply and compare with rated power
dissipation. Even better, look at SOA curves for your application.

Tim.

 

[Watson A.Name \"Watt Sun]

Tim Shoppa wrote:

"Watson A.Name \"Watt Sun - the Dark Remover\"" <NOSPAM@dslextreme.com> wrote in message news:<bogfcu$4p3bu$1@hades.csu.net>...

The Zetex part has way lower Vce at saturation (both "typical" and
"guaranteed".) Whether that's relevant to you or not, I don't know.

Have you checked the specs for the 2SD965? It'll handle 5 amps.
Presumably at 3A (the max that the Zetex will handle), it'll have lower
Vce(sat). Yeah, it's relevant, the main reason to use these transistors.

Yes, I looked at the two curves and specs. The Zetex has much lower
Vce(sat) than the 2SD965 at both 3 and 5 Amps:

2SD965 ZTX649

1A .4V typ .1V typ
.3V guaranteed

3A .6V typ
1.V guaranteed .35V typ

5A 1.2V typ .55V typ

Remember that even though the 2SD965 is rated at 5 Amps, with a 1.2V Vce(sat)

I don't believe it has that high a Vce(sat), 1.2V. You're probably
looking at the Vbe.

And also, consider the Ic/Ib ratio that both were measured at. If you
decrease the ratio, the Vce(sat) is even less.

at 5 Amps it'll be dissipating 6 Watts, which is six times its avg power
rating. Again, whether this is relevant or not to you will depend on
your duty cycle.

In short: don't look at Ic(max), look at your collector current and
the Vce(sat) at that current, multiply and compare with rated power
dissipation. Even better, look at SOA curves for your application.

Tim.

 

[Watson A.Name - "Watt Sun]

In article <bec993c8.0311071132.19de3757@posting.google.com>,
shoppa@trailing-edge.com mentioned...

"Watson A.Name \"Watt Sun - the Dark Remover\"" <NOSPAM@dslextreme.com> wrote in message news:<bogfcu$4p3bu$1@hades.csu.net>...
The Zetex part has way lower Vce at saturation (both "typical" and
"guaranteed".) Whether that's relevant to you or not, I don't know.

Have you checked the specs for the 2SD965? It'll handle 5 amps.
Presumably at 3A (the max that the Zetex will handle), it'll have lower
Vce(sat). Yeah, it's relevant, the main reason to use these transistors.

Yes, I looked at the two curves and specs. The Zetex has much lower
Vce(sat) than the 2SD965 at both 3 and 5 Amps:

I have retrieved the 2SD965 data sheet from my PC at home, and checked
it. The typical values you show below are incorrect, and way out of
line with the data sheet. I have inserted the actual values from the
data sheet, or from the graphs on the data sheet.

2SD965 ZTX649

1A .4V typ .1V typ

1A .12V typ (Ic/Ib = 30) (difficult to read the graph,
might be lower)

.3V guaranteed

3A .6V typ
1.V guaranteed .35V typ

3A .28V typ (Ic/Ib = 30)

5A 1.2V typ .55V typ

Notice that these are at Ic/Ib = 30. The Vce(sat) measurement is
usually done at 10, which would give even _lower_ values. If you have
any doubts, I'll be glad to show you the actual Panasonic data sheet.
The Panasonic document number is SJC00200BED, Pub date is Jan 2003.

Remember that even though the 2SD965 is rated at 5 Amps, with a 1.2V Vce(sat)
at 5 Amps it'll be dissipating 6 Watts, which is six times its avg power
rating. Again, whether this is relevant or not to you will depend on
your duty cycle.

In short: don't look at Ic(max), look at your collector current and
the Vce(sat) at that current, multiply and compare with rated power
dissipation. Even better, look at SOA curves for your application.

Tim.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Tim Shoppa]

Watson A.Name - "Watt Sun, Dark Remover" <alondra101@hotmail.com> wrote in message news:<MPG.1a164d4f49d89b499898c8@news.dslextreme.com>...

I have retrieved the 2SD965 data sheet from my PC at home, and checked
it. The typical values you show below are incorrect, and way out of
line with the data sheet.

And I just re-checked with the Unisonic data sheet I have, and the numbers
I quoted are straight from Fig 4 there. Maybe the Panasonic parts you bought
are far superior.

Tim.

 

[Watson A.Name - "Watt Sun]

In article <bec993c8.0311081034.1f5dce1a@posting.google.com>,
shoppa@trailing-edge.com mentioned...

Watson A.Name - "Watt Sun, Dark Remover" <alondra101@hotmail.com> wrote in message news:<MPG.1a164d4f49d89b499898c8@news.dslextreme.com>...
I have retrieved the 2SD965 data sheet from my PC at home, and checked
it. The typical values you show below are incorrect, and way out of
line with the data sheet.

And I just re-checked with the Unisonic data sheet I have, and the numbers
I quoted are straight from Fig 4 there. Maybe the Panasonic parts you bought
are far superior.

As far as I know, the 2SD965 is a Panasonic aka Matsushita transistor,
and other sources are second sources. And any second source should
make their part conform to the original mfgr's data sheet, if they
expect to use the original part number. In this case, the 2SD965 is
registered with JIS, so it's improper for another mfgr to deviate from
the original specs.

I might have cut Unisonic some slack if they had labeled their part
KSD965 like Fairchild does with some of their 2SC and similar
substitute transistors. But in this case, they're undeserving.

I searched and searched the Panasonic websites for the data sheet for
the 2SD965 without any positive results. So I'll post the .PDF to
alt.binaries.schematic.electronic in a few minutes.

Tim.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Fred Abse]

On Sat, 08 Nov 2003 17:59:10 -0800, Watson A. Name - "Watt Sun, Dark
Remover" wrote:

As far as I know, the 2SD965 is a Panasonic aka Matsushita transistor, and
other sources are second sources. And any second source should make their
part conform to the original mfgr's data sheet, if they expect to use the
original part number. In this case, the 2SD965 is registered with JIS, so
it's improper for another mfgr to deviate from the original specs.

I understood that JIS register a number to *one* manufacturer only, and it
is improper for another to use it, even for an exactly similar device. Is
this not correct?

--
Then there's duct tape ...
(Garrison Keillor)
nofr@sbhevre.pbzchyvax.pb.hx

 

[Watson A.Name - "Watt Sun]

In article <pan.2003.11.09.13.04.44.121897@cerebrumconfus.it>,
excretatauris@cerebrumconfus.it mentioned...

On Sat, 08 Nov 2003 17:59:10 -0800, Watson A. Name - "Watt Sun, Dark
Remover" wrote:

As far as I know, the 2SD965 is a Panasonic aka Matsushita transistor, and
other sources are second sources. And any second source should make their
part conform to the original mfgr's data sheet, if they expect to use the
original part number. In this case, the 2SD965 is registered with JIS, so
it's improper for another mfgr to deviate from the original specs.

I understood that JIS register a number to *one* manufacturer only, and it
is improper for another to use it, even for an exactly similar device. Is
this not correct?

All the Japanese transistors for which I've downloaded data sheets,
I've never seen one that has more than a single a Japanese mfgr. But
of course all that doesn't apply if you're a mfgr in another country.
Philips makes transistors that have numbers like C1815 (I have one in
my hand), and their data sheet is identical to the Japanese mfgr,
Toshiba. KEC, Korea Electronics Co, seems to be a spinoff of Toshiba,
so may make the C1815, but maybe under license to Toshiba. Fairchild
makes KSC whatever transistors, same as 2SC whatever.

Two of the Japanese mfgrs have joined, so that could confuse things
somewhat.


--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@

 

[Tim Shoppa]

Watson A.Name - "Watt Sun, Dark Remover" <alondra101@hotmail.com> wrote in message news:<MPG.1a186193cd76b78a9898db@news.dslextreme.com>...

In article <pan.2003.11.09.13.04.44.121897@cerebrumconfus.it>,
excretatauris@cerebrumconfus.it mentioned...
On Sat, 08 Nov 2003 17:59:10 -0800, Watson A. Name - "Watt Sun, Dark
Remover" wrote:

As far as I know, the 2SD965 is a Panasonic aka Matsushita transistor, and
other sources are second sources. And any second source should make their
part conform to the original mfgr's data sheet, if they expect to use the
original part number. In this case, the 2SD965 is registered with JIS, so
it's improper for another mfgr to deviate from the original specs.

I understood that JIS register a number to *one* manufacturer only, and it
is improper for another to use it, even for an exactly similar device. Is
this not correct?

All the Japanese transistors for which I've downloaded data sheets,
I've never seen one that has more than a single a Japanese mfgr. But
of course all that doesn't apply if you're a mfgr in another country.

Just searching for 2SD965 on the web, I see a company called Wing-Shing
makes a TO-92 transistor called that in Hong Kong, and Unisonic in Taiwan
makes them in TO-252 and SOT-89. None of these are Japanese companies
so I'm guessing that none are "Japanese Official".

When I buy 2SA/2SB/2SC/2SD transistors from MCM etc., they are only
occasionally Japanese in origin. Almost all the ones I get now are
Taiwan or Hong Kong and a few are Chinese lately. Some are stamped
"Mexico" but not as much as ten years ago.

I never liked the Japanese numbering system - they're obviously done
to favor manufacturers, not to give buyers any real choice. I'm not a
huge fan of JAN 2N numbers either, but they seem to make more sense from
a purchasing standpoint. With the vast majority of 2N-like numbers (PN,
MPS, etc.) these days not actually meeting the JAN specs (because they're
plastic, not metal cans) maybe the situation is more murky than my vague
opinions

Tim.

 

[Watson A.Name - "Watt Sun]

In article <bec993c8.0311100734.36736746@posting.google.com>,
shoppa@trailing-edge.com mentioned...

Watson A.Name - "Watt Sun, Dark Remover" <alondra101@hotmail.com> wrote in message news:<MPG.1a186193cd76b78a9898db@news.dslextreme.com>...
In article <pan.2003.11.09.13.04.44.121897@cerebrumconfus.it>,
excretatauris@cerebrumconfus.it mentioned...
On Sat, 08 Nov 2003 17:59:10 -0800, Watson A. Name - "Watt Sun, Dark
Remover" wrote:

As far as I know, the 2SD965 is a Panasonic aka Matsushita transistor, and
other sources are second sources. And any second source should make their
part conform to the original mfgr's data sheet, if they expect to use the
original part number. In this case, the 2SD965 is registered with JIS, so
it's improper for another mfgr to deviate from the original specs.

I understood that JIS register a number to *one* manufacturer only, and it
is improper for another to use it, even for an exactly similar device. Is
this not correct?

All the Japanese transistors for which I've downloaded data sheets,
I've never seen one that has more than a single a Japanese mfgr. But
of course all that doesn't apply if you're a mfgr in another country.

Just searching for 2SD965 on the web, I see a company called Wing-Shing
makes a TO-92 transistor called that in Hong Kong, and Unisonic in Taiwan
makes them in TO-252 and SOT-89. None of these are Japanese companies
so I'm guessing that none are "Japanese Official".

When I buy 2SA/2SB/2SC/2SD transistors from MCM etc., they are only
occasionally Japanese in origin. Almost all the ones I get now are
Taiwan or Hong Kong and a few are Chinese lately. Some are stamped
"Mexico" but not as much as ten years ago.

I never liked the Japanese numbering system - they're obviously done
to favor manufacturers, not to give buyers any real choice. I'm not a
huge fan of JAN 2N numbers either, but they seem to make more sense from
a purchasing standpoint. With the vast majority of 2N-like numbers (PN,
MPS, etc.) these days not actually meeting the JAN specs (because they're
plastic, not metal cans) maybe the situation is more murky than my vague
opinions

Did you check out the data sheet I posted to ABSE? I know from using
the 965s that they do very well at high currents, and the high gain
makes them use less current for base bias, which helps efficiency a
bit. I got them (real Panasonic) from BDent.com but you can find them
in just about every disposable flash camera. I'll have to check out
MCM. Tnx.

Tim.

--
@@F@r@o@m@@O@r@a@n@g@e@@C@o@u@n@t@y@,@@C@a@l@,@@w@h@e@r@e@@
###Got a Question about ELECTRONICS? Check HERE First:###
http://users.pandora.be/educypedia/electronics/databank.htm
My email address is whitelisted. *All* email sent to it
goes directly to the trash unless you add NOSPAM in the
Subject: line with other stuff. alondra101 <at> hotmail.com
Don't be ripped off by the big book dealers. Go to the URL
that will give you a choice and save you money(up to half).
http://www.everybookstore.com You'll be glad you did!
Just when you thought you had all this figured out, the gov't
changed it: http://physics.nist.gov/cuu/Units/binary.html
@@t@h@e@@a@f@f@l@u@e@n@t@@m@e@e@t@@t@h@e@@E@f@f@l@u@e@n@t@@