grhughes said:
Very good transistors.
Along with TO-220, MJE15030 / MJE15031
these TO-126 are the most used as Drivers for Audio Output stages.
They are also often used as thermal sensors, placed on the heatsink.
To avoid thermal 'runaway' and overheating.
They do excellent compared to most alternative transistors
in my Audio Amplifiers simulations!
They are old, yes. There are newer surface mounted versions of these.
Even though old, they compete very well.
Maybe because there just isn't too many good audio driver complementary NPN/PNP around.
lineup
grhughes said:
You need to be aware that there are genuine Philips BD139 and BD140 - both are excellent devices (essentially these are BC639 and BC640 in TO126 package) and there are many other devices carrying these numbers - namely from ST, Samsung and many others, all of which are not very good at all from my experience. None of these "clone" manufacturers would give Ft parameter in their datasheet (Philips ones are rated at 160 MHz) and the device capacitances are about twice of the values for Philips (now NXT http://www.nxp.com )
Here is the link for Philips datasheets:
http://www.nxp.com/acrobat_download/datasheets/BD136_138_140_3.pdf
http://www.nxp.com/acrobat_download/datasheets/BD135_137_139_3.pdf
Unfortunately, these good transistors are no longer in production. So, if you are sure that you'll get proper Philips BD139/140 transistors - use them, otherwise I wouldn't touch these "clones" - they are not really good for anything, IMHO - even in a voltage regulator.
Cheers
x-pro
Back in the old days you had to open a semiconductor book to look at a datasheet, instead of clicking a pdf.
Of course, the semiconductor data book comes free if you've got a relative employed at the Philips NatLab in Eindhoven.
Free online datasheets often are abbreviated versions, sometimes saves you 10 to 14 pages.
A bunch of BD139/140s in parallel make a fantastic class A headphone amp output stage.
Philips versions are much nicer, Cob of 5.7pF, downside that the power they handle is 2/3d of the different die version.
Of course, the semiconductor data book comes free if you've got a relative employed at the Philips NatLab in Eindhoven.
Free online datasheets often are abbreviated versions, sometimes saves you 10 to 14 pages.
A bunch of BD139/140s in parallel make a fantastic class A headphone amp output stage.
Philips versions are much nicer, Cob of 5.7pF, downside that the power they handle is 2/3d of the different die version.
jacco vermeulen said:
"Different die version" is a completely different transistor altogether which by accident shares the name with the original Philips device. Most annoying is the fact that these are much slower devices that Philips and would perform considerably poorer in audio. It is indeed 12W device (Philips is 8W) and no Ft rating at all.
x-pro
Re: Yes, I have the datasheet. ........
I would recommend these devices:
http://www.nxp.com/acrobat_download/datasheets/BC640_BCP53_BCX53_6.pdf
http://www.nxp.com/acrobat_download/datasheets/BC639_BCP56_BCX56_7.pdf
unless you will get original Philips BD139/BD140 - the same die in TO126 case.
Cheers
x-pro
grhughes said:
I would recommend these devices:
http://www.nxp.com/acrobat_download/datasheets/BC640_BCP53_BCX53_6.pdf
http://www.nxp.com/acrobat_download/datasheets/BC639_BCP56_BCX56_7.pdf
unless you will get original Philips BD139/BD140 - the same die in TO126 case.
Cheers
x-pro
Devices from other manufacturers usually carry a logo.
For instance: ST(Samsung) or SGS (Thomson), since 1987 one and the same company.
Most have the printing vertically on the device, an exception is an On/Motorola which looks very similar to the Philips device.
Philips devices have horizontal labels, either no logo or something like phi scribbled unreadable in front of the hFe ranking. See example picture, i'll post you a better/sharper one later on=>
ps:
i haven't spent a second keeping track on such devices in 20 years time as i've only used the Philly parts since, please correct me if i flunked the exam. The lines above are taken from the brainwash bank.
Amusing crumb: it was a German audio designer who pointed me to not using any other than the Phi devices.
For instance: ST(Samsung) or SGS (Thomson), since 1987 one and the same company.
Most have the printing vertically on the device, an exception is an On/Motorola which looks very similar to the Philips device.
Philips devices have horizontal labels, either no logo or something like phi scribbled unreadable in front of the hFe ranking. See example picture, i'll post you a better/sharper one later on=>
ps:
i haven't spent a second keeping track on such devices in 20 years time as i've only used the Philly parts since, please correct me if i flunked the exam. The lines above are taken from the brainwash bank.
Amusing crumb: it was a German audio designer who pointed me to not using any other than the Phi devices.
Attachments
stoolpigeon said:
On top of what already was written by jacco, I would add that it is possible to check the capacitances of the device if you have a capacitance meter. If my memory serves me right, Philips BD140 would have B-C capacitance about 50-60pF at 0V, and ST etc. - about 100-120 pF. In any case the capacitances on BC640 and Philips BD140 (and their NPN complements BC639/BD139) are near identical.
x-pro
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