If these are supposed to be from the same manufacturer, then it seems a little strange that the logo is slightly different on each device. I would be suspicious but I don't know which one is correct.
Yes, if you look at black plastic part, you will see it.AndrewT said:
BTW dont you think that it is so small for that kind of transistors or it is normal size?
Hi,
they do a low power To92 version of this transistor with what appear to be identical characteristics.
If this is indeed a high power version, then we would expect the chip to be smaller than the norm, but that does strike me as very small.
they do a low power To92 version of this transistor with what appear to be identical characteristics.
If this is indeed a high power version, then we would expect the chip to be smaller than the norm, but that does strike me as very small.
Hi,
these are not carrying the characteristic etched marking method and shape of molded case always used, not genuine Hitachi...
Andrew,
Who? The Caribbean pirates? The TO-92 package is simply inappropriate for this transistor and never announced or manufactured by Hitachi.
Its properties are specified, for different properties another designation is assigned.
these are not carrying the characteristic etched marking method and shape of molded case always used, not genuine Hitachi...
Andrew,
Who? The Caribbean pirates? The TO-92 package is simply inappropriate for this transistor and never announced or manufactured by Hitachi.
Its properties are specified, for different properties another designation is assigned.
These are from a lot I received several years ago -- they are in Hitachi boxes and Hitachi plastic bags -- these devices are not in the current Renesas (Hitachi) family.
An externally hosted image should be here but it was not working when we last tested it.
well, i think that the Hitachi devices are going to be unobtanium after a while -- I have tested the PMC devices from Singapore and they match up pretty well -- but my testing hasn't been that extensive.
AndrewT said:
Hi Lumba,
go and have a look at the Hitachi 2sb647a datasheet.
Most of the data is very close to that for 2sb649, except for the voltage, current and power derating to match the To92 package.
I contend that this same chip could well be used in both devices with just the copper backplate increased to allow the extra dissipation.
But, I could be wrong.
You are probably right, it wouldn't be the first time this was done. just look at the venerable BD139/140 and it's TO92 version, BC639/640.
The chip looks small, but I doubt the real thing is very big, perhaps a bit over 1mm square. The writing is odd, looks like laser cut or etched, the genuine devices are similar but very shallow (almost like print).
The chip looks small, but I doubt the real thing is very big, perhaps a bit over 1mm square. The writing is odd, looks like laser cut or etched, the genuine devices are similar but very shallow (almost like print).
Hi Andrew,
OK, now I understand what you mean and YES you are very much right. Manufacturers use often transistor chip designs in several different packages resulting in recognizable similarities.
The package of 2SB647 is TO-92L
Other nice devices from Hitachi I would like to mention: 2SD756 2SC1213 2SC1775 2SD1609 and their complementary pairs.
- That`s superior Japanese technology.
Kindly regards
OK, now I understand what you mean and YES you are very much right. Manufacturers use often transistor chip designs in several different packages resulting in recognizable similarities.
The package of 2SB647 is TO-92L
Other nice devices from Hitachi I would like to mention: 2SD756 2SC1213 2SC1775 2SD1609 and their complementary pairs.
- That`s superior Japanese technology.
Kindly regards
AndrewT said:
Yes you are right, look at attachment, but now I am so confused, is it genuine Hitachi transistor or not
Hi,
have you seen Zetec's 3A transistors built into the Eline package?
Some SMDs have similar spec in the sot23 and 223 packages.
It appears that the chips can cope if the heat can get out.
Think about the relative size of a big power transistor and the much bigger heatsink to keep it cool. Same philosophy, but on a different scale.
have you seen Zetec's 3A transistors built into the Eline package?
Some SMDs have similar spec in the sot23 and 223 packages.
It appears that the chips can cope if the heat can get out.
Think about the relative size of a big power transistor and the much bigger heatsink to keep it cool. Same philosophy, but on a different scale.
Zeljko,
Only Hitachi`s manufacturing technology should be trusted.
The operating area and dissipation level of devices in audio use, in general terms and especially versus data sheets, would be another issue.
Do not be. UTC is a Taiwanese pirate.
Only Hitachi`s manufacturing technology should be trusted.
Actually 1.5A
The operating area and dissipation level of devices in audio use, in general terms and especially versus data sheets, would be another issue.
Andrew,
Kindly regards
Maybe it can for a while, but I would not like to listen to the sound produced.
Kindly regards
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